Forum Posts

Ryan Eckert, MS, CSCS
Mar 31, 2022
In The VO2 Max Forum
Brief Overview of Low-Carbohydrate, High-Fat Diets for Endurance Athletes Current sports nutrition guidelines from leading nutrition and exercise organizations around the globe (4,5) recommend a high-carbohydrate, low-fat (HCLF) diet for endurance athletes that broadly consists of: ~50-60% of energy intake from carbohydrates ~15-20% of energy intake from protein The remaining (~20-35%) energy intake from fat However, since the early 1980’s, researchers have been interested in the potential benefits of a low-carbohydrate, high-fat (LCHF) for endurance athletes. Studies investigating the effects of LCHF diets have their origins in the management of type 2 diabetes, the management of epileptic seizures, and the potential management of obesity (2). However, in 1983, Phinney and colleagues (3) were the first to test the impacts of a LCHF on endurance athletes. Researchers thereafter discovered in the next decade or so that LCHF diets did not really demonstrate any efficacy for improving endurance performance. However, there has been a renewed interest in LCHF diets for endurance athletes, particularly the more extreme version of the LCHF diet, a ketogenic LCHF (K-LCHF) diet. A typical LCHF diet might consist of an energy intake ratio of >60% of calories from fat and <25% of calories from carbohydrates. However, a K-LCHF diet would restrict an athlete to consuming <5% of their calorie intake from carbohydrate in order to promote a state of ketosis, wherein the body derives much of its energy from fat and ketones as opposed to glucose. In a December 2019 Science Post, I discussed in great depth the proposed mechanisms behind the LCHF diet as well as provided an in-depth review of the research literature surrounding this topic up to that point. I will, therefore, spare the in-depth overview herein and refer you to this post for more background on the topic and origins of LCHF diets for endurance athletes. If you are not familiar with LCHF diets and the proposed mechanisms of action, I would strongly suggest you read this previous post before reading further. Some of the key takeaways from the research that was available prior to 2019 was as follows: LCHF diets had minimal evidence to document any superiority to a traditional HCLF diet for endurance performance. LCHF diets may impair an endurance athlete’s ability to do high-intensity work in training and in racing due to an impaired ability to derive energy from glucose or glycogen (i.e., glycolysis). There is some possibility of a LCHF diet to improve performance in ultra-endurance athletes that train and race at very, very low intensities for extremely prolonged periods of time that rarely ever do work at an intensity above 60-65% of their VO2 max (e.g., multi-day adventure racers), which is an extremely low intensity compared to what most endurance athletes race at for single-day events (e.g., trail runs, road runs, triathlons, etc.). Since 2019, however, more research has emerged on the topic of LCHF or K-LCHF diets for endurance athletes. Therefore, it is worth revisiting this topic given its resurging popularity in some realms of the endurance world, particularly in the long-distance triathlon space (e.g., half-distance and full-distance triathlons). What Does the Latest Research Say? I often turn to systematic reviews and meta-analyses for summaries of evidence on topics of interest to me, and this is exactly what I did here. There was a great systematic review and meta-analysis recently published in 2021 by Cao and colleagues (2) summarizing the effects of K-LCHF diets on aerobic capacity and exercise performance among endurance athletes. This article included 10 total individual studies for analysis consisting of 139 endurance athletes, albeit these athletes were primarily male (a potential limitation). The primary outcomes assessed in this systematic review and meta-analysis were related to the impact of a K-LCHF diet on the following exercise-related variables: Aerobic capacity (i.e., VO2 max) as assessed by a graded exercise test (GXT) Time to exhaustion (TTE) on GXT Maximum heart rate (HR) achieved during GXT Respiratory exchange ratio (RER) on GXT In brief, the authors found no significant effect of a K-LCHF diet on aerobic capacity, TTE, nor maximum HR; however, there was a large shift towards greater fat metabolism during a GXT as evidenced by a large reduction in RER among those following a K-LCHF diet (lower RER indicates greater reliance on fat oxidation). These findings are very similar to the larger body of LCHF literature in that a LCHF diet shows no real benefit on markers of endurance performance or fitness. However, a LCHF diet does show a dramatic increase in the athlete’s capacity for fat oxidation, but often at the expense of a reduced capacity for glycolysis, or the generation of energy from carbohydrates. This latter shift is not necessarily performance-enhancing as many propose it to be as the available research just doesn’t show a greater shift in fat metabolism to be associated or linked with any sort of enhancement in endurance performance or fitness markers. This recent systematic review and meta-analysis lends more evidence to support this case. A recently published study by Burke and colleagues (1) sheds some further insight into LCHF diets and endurance performance on a more granular level, and hints at what I think the true potential of LCHF diets is for endurance athletes (discussed later on below). In this study, researchers enrolled 13 elite/professional race walkers, some of whom compete at the Olympic level. These 13 race walkers all went through 3 phases in this research study, and these phases were as follows: Phase 1: All 13 athletes completed baseline fitness and performance tests (VO2 max testing, walking economy testing, and a 10,000-m race on a track), followed by a 5-day HCLF diet to establish a baseline dietary intake, and finally completing phase 1 with a 25-km “long” walk where fitness metrics were recorded (RER, HR, RPE, and more). Phase 2: The 13 athletes were divided into a HCLF group (n=6) or a K-LCHF group (n=7) for 5 days followed by a repeat of baseline fitness and performance measures (VO2 max testing, walking economy testing, a 10,000-m race on a track, and a 25-km “long” walk). Phase 3: Finally, all athletes then went back to a HCLF “restoration” diet for 5 days and finished this 3rd phase with another 25-km “long” walk where fitness metrics were recorded (RER, HR, RPE, and more). In brief, the researchers found the following after administering this dietary intervention among these elite-level race walkers: 5-6 days of adaptation to a K-LCHF diet was sufficient to increase exercise fat oxidation rates previously seen with longer-term K-LCHF dietary interventions (>12 weeks); this indicates that full adaptation to a K-LCHF may take place quickly and potentially dispels the notion that adaptation to a LCHF diet takes a long time (>12 weeks) and is why most research to date does not demonstrate benefits in favor of LCHF or K-LCHF diets. Increases in fat oxidation among the K-LCHF group was also seen alongside a reduction in exercise efficiency, as evident with a 5-8% increase in oxygen cost at the race walkers 10,000-m race performances; this is rather significant as long-distance endurance events are heavily reliant on being as efficient as possible, so a reduction in exercise efficiency may have a significant negative impact on performance. Acute restoration of glycogen stores with a 1-day HCLF restoration period prior to a key performance was not enough to “outweigh” the negative impacts of a K-LCHF on 10,000-m race performance; this was evident by carbohydrate oxidation rates only reaching 61-78% of baseline values established with all athletes were on the standard HCLF diet. High-intensity exercise performance was impaired in those on the K-LCHF diet, and acute restoration of glycogen stores was not sufficient to improve high-intensity exercise capacity to baseline values seen when all athletes were on the HCLF diet. The findings herein from this study have now been pretty clearly replicated over and over and over again, and the moral of the story remains pretty much the same as what I stated back in my 2019 post on this topic and what I stated in the introduction of this current post, of which I will state them again with some underlining to emphasize important points: LCHF diets had minimal evidence to document any superiority to a traditional HCLF diet for endurance performance. LCHF diets may impair an endurance athlete’s ability to do high-intensity work in training and in racing due to an impaired ability to derive energy from glucose or glycogen (i.e., glycolysis). There is some possibility of a LCHF diet to improve performance in ultra-endurance athletes that train and race at very, very low intensities for extremely prolonged periods of time that rarely ever do work at an intensity above 60-65% of their VO2 max (e.g., multi-day adventure racers), which is an extremely low intensity compared to what most endurance athletes race at for single-day events (e.g., trail runs, road runs, triathlons, etc.). I would also like to add one additional take-home message that seems to be emerging from the data as more studies are done on this topic: There seem to be a very small subset of endurance athletes that respond positively to a LCHF or K-LCHF diet, demonstrating improvements in performance despite reduced carbohydrate oxidation capacity. In the Burke and colleagues study discussed just above (1), when looking at some of the individual-level data amongst the 13 athletes, there was one single athlete that seemed to perform better in their 10,000-m race performance. This is also a typical finding in these sorts of studies. The majority of athletes do not improve their performance and usually perform worse when on a LCHF or K-LCHF diet, but there is usually one or two athletes that actually do see small improvements. This is where I am starting to see the potential utility of a LCHF/K-LCHF diet for endurance athletes and starts getting at the genetic variability in the response to dietary interventions. It is also for this reason that dietary protocols are not a one-size-fits-all. Yes, based on the research we currently have, a “standard” HCLF diet seems to be what most endurance athletes should be following as this diet seems to produce optimal performance across a range of endurance distances and disciplines, but there is a very, very small minority (~5%) of endurance athletes that may, just may, see some performance improvement/optimization when on a LCHF or K-LCHF diet. However, I say this with caution as there are other risks to adopting a high-fat diet related to overall health and well-being that are sometimes not captured in all the studies done in this area, namely the increased risk of illness (e.g., upper respiratory tract infection) and reported negatively impacted mood that is sometimes seen in athletes undergoing a high-fat dietary protocol. Adequate carbohydrate availability and a reliance on glucose at rest seems to be related to optimal functioning of various bodily systems and functions, and it may be that, even if an athlete performs better in a lab or in a race, they may still experience negative health consequences as a side effect. More research indeed needs to be done in this area. Conclusions So, there you have it. I hope this provides a rather concise update on the state of the LCHF literature and allows you to walk away with a better understanding of this topic more broadly. As with almost anything in life, let alone sport, things are rarely black and white or cut and dry. Things tend to fall more in the middle, and dietary interventions are no different. Diet can elicit strong emotions and reactions from athletes, with some dietary principles being held in an almost dogmatic or religious light among many, but I strongly encourage you to be open-minded when reading this and when reading other nutrition-related research as nutrition can be very, very individual. While a HCLF diet may work best for most, there could certainly be some that function best on a LCHF diet. The same can be said for many other dietary approaches, from veganism, to vegetarianism, etc. Just because it works for you or worked for someone else, does not mean it works for everyone. However, I would still strongly encourage the vast majority of endurance athletes to eat a HCLF diet for optimal performance and health… of which I can cheers (over a pastry or two) to that! References: Burke LM, Whitfield J, Heikura IA, Ross ML, Tee N, Forbes SF, Hall R, McKay AK, Wallett AM, Sharma AP. Adaptation to a low carbohydrate high fat diet is rapid but impairs endurance exercise metabolism and performance despite enhanced glycogen availability. The Journal of Physiology. 2021 Feb;599(3):771-90. Cao J, Lei S, Wang X, Cheng S. The Effect of a Ketogenic Low-Carbohydrate, High-Fat Diet on Aerobic Capacity and Exercise Performance in Endurance Athletes: A Systematic Review and Meta-Analysis. Nutrients. 2021 Aug;13(8):2896. Phinney SD, Bistrian BR, Evans WJ, Gervino E, Blackburn GL. The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism. 1983 Aug 1;32(8):769-76. Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics. 2016 Mar 1;116(3):501-28. Vitale K, Getzin A. Nutrition and supplement update for the endurance athlete: review and recommendations. Nutrients. 2019 Jun;11(6):1289. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Low-Carbohydrate, High-Fat (LCHF) Diets and Endurance Performance: an Update on Emerging Research content media
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Ryan Eckert, MS, CSCS
Mar 01, 2022
In The VO2 Max Forum
What is Ashwagandha Ashwagandha might be an herb you have never heard of, but it is time that you hear about it! I became interested in using Ashwagandha for its various medicinal properties, namely the evidence-based beneficial effects of this compound on stress and mood. To my surprise however, as I started diving into a bit of the research surrounding the health benefits of Ashwagandha, I started to notice that it had also been studied as a potential performance-enhancing substance for athletes. Ashwagandha (Withania somnivera) is a popular herb used in Ayurvedic medicine due to its wide-ranging biological actions influencing health (Mishra et al., 2000). It is known as an “adaptogen”, which is considered any nontoxic substance, especially plant extracts, that is known to increase the body’s ability to resist the damaging effects of stress and promote or restore bodily homeostasis. Many different plants are considered to have adaptogenic properties, including things such as various strains of mushrooms and other fungi. Ashwagandha is one of the more popular adaptogenic herbs that is both used in practice and studied in the scientific literature. However, it has only been recently studied for its possible beneficial effects on athletic performance. The findings of this research might just surprise you as it surprised me, namely because I would not have expected an herb to have the effects that have been documented in recent scientific literature. So, without further ado, let’s dive into that research! Ashwagandha and Endurance Performance A recent 2020 systematic review and meta-analysis (Pérez-Gómez et al., 2020) aimed to summarize the effects of ashwagandha supplementation on VO2 Max in healthy adults and athletes. This study ultimately included five studies with 162 total participants ranging in age from 16-45 years of age. Study participants were a mix of healthy adults, various recreational athletes, and elite cyclists. So, this review and meta-analysis included quite a diverse population despite a relatively small total sample size. Researchers found that the studies included in this review utilized 500-1000 mg of Ashwagandha daily for 2-12 weeks. The meta-analysis found a significant beneficial effect of Ashwagandha compared to placebo control in the order of 3.0 ml/kg/min. This essentially means that taking Ashwagandha favored a 3.0 ml/kg/min improvement in VO2 Max at study treatment end. For anyone that knows anything about VO2 Max, this is a rather significant real-world difference in VO2 Max. Athletes will spend months or years trying to increase their VO2 Max by a few points, so to have Ashwagandha consumption for a few weeks to a few months lead to a favorable impact on VO2 Max in the order of 3.0 points higher than a placebo control group is very exciting. This meta-analysis, however, had some limitations, including the small sample size and the relatively poor overall quality of evidence as calculated by the authors when conducting the meta-analysis. Therefore, these results should be interpreted with caution. Another more recent 2021 systematic review and meta-analysis (Bonilla et al., 2021) aimed to assess the effects of Ashwagandha on physical performance, including VO2 Max and blood hemoglobin concentration (Hb) in healthy individuals. This review/meta-analysis included 12 studies and over 600 healthy adults. Sub-group meta-analysis for VO2 Max demonstrated a significant and very large effect of Ashwagandha compared to placebo control (d = 1.929; p < 0.001). A separate sub-group meta-analysis for Hb also revealed a significant and very large effect of Ashwagandha compared to placebo control (d = 1.697; p < 0.001). This particular meta-analysis had a much higher quality of evidence than the previously discussed 2020 review/meta-analysis, and so the findings of this paper can be interpreted with greater confidence. This is great, as the treatment effect of Ashwagandha on VO2 Max and Hb were significant and very large compared to the placebo control! Conclusions So, what do we make of all this? It seems, based on the two systematic reviews and meta-analyses discussed above, that Ashwagandha has a significant and large treatment effect on endurance performance markers, specifically VO2 Max and Hb. VO2 Max is an important marker/characteristic of endurance performance, and so a higher VO2 Max due to the addition of Ashwagandha is potentially significant in real-world competition. A greater blood hemoglobin concentration is also potentially significant in real-world competition for endurance athletes as greater Hb is related to a greater oxygen-carrying capacity, which can improve endurance performance. It is important to point out that there have not been any studies that have really investigated the impact of Ashwagandha on real-world performance in a race or time trial. So, the above findings should not be interpreted to say that Ashwagandha improves endurance performance, per se, as that research has not been done. However, Ashwagandha does seem to have beneficial effects on markers of endurance performance, and so it is theoretically possible that these improved endurance characteristics could ultimately lead to better real-world performance in a race or competition. Ashwagandha also tends to be a relatively affordable supplement, with a high-quality Ashwagandha supplement from Gaia Herbs being only ~$24 on Amazon.com (at the time this was written and published in early 2022). Research tends to suggest a beneficial effect of Ashwagandha when taken regularly at doses of 500-1000 mg, and this Gaia Herbs supplement would last an athlete 60 days when taken at that dosage range. This is only ~$12/month for a potentially ergogenic, and completely legal for competition, substance. This makes it a potentially attractive option for athletes. And the added benefit is that Ashwagandha has evidence supporting general health benefits, including beneficial effects on stress. Athletes are constantly under stress from training, and so managing stress and recovery from said stress through sleep, nutrition, and possibly supplementation can help an athlete perform at their best. Ashwagandha seems to help improve not only performance, but also counteract and manage stress at a relatively low cost. Ashwagandha is also safe when taken orally in doses of up to 1000 mg/day, with minimal risk of side effects (mild sedative effect can be seen in some individuals; Examine, 2022). However, it is typically recommended to take Ashwagandha for no more than 3 months at a time as the body can develop a tolerance to it and the beneficial effects can decrease long-term (Examine, 2022). Therefore, a sensible approach for supplementing with Ashwagandha could be to take 500-1000 mg/day for 2-3 months with a 1-2 month “wash-out” period before cycling back on the supplement again. As with any supplement, it is a good idea to talk to a healthcare professional to make sure there are no contraindications to you taking Ashwagandha. Despite it being a very safe supplement with little risk of any adverse side effects, it can react with certain medications, and so if you are taking any medications for your health, it is worthwhile checking with your doctor before starting any supplement. And finally, as with any supplement, it is always more important to optimize your diet first before relying on supplements. Although Ashwagandha is not normally found in foods consumed within a nutritious diet, a good diet is always the place to start when looking to maximize adaptations to and recovery from endurance training. So, start with your diet and then consider supplementing with various evidence-based supplements if you have the budget and willingness to do so. References: Bonilla DA, Moreno Y, Gho C, Petro JL, Odriozola-Martínez A, Kreider RB. Effects of Ashwagandha (Withania somnifera) on Physical Performance: Systematic Review and Bayesian Meta-Analysis. Journal of Functional Morphology and Kinesiology. 2021 Mar;6(1):20. Examine. Ashwagandha. Updated Jan, 6, 2022. Retrieved from: https://examine.com/supplements/ashwagandha/ Mishra, L.C.; Singh, B.B.; Dagenais, S. Scientific basis for the therapeutic use of Withania somnifera (ashwagandha): A review. Altern. Med. Rev. 2000, 5, 334–346. Pérez-Gómez J, Villafaina S, Adsuar JC, Merellano-Navarro E, Collado-Mateo D. Effects of Ashwagandha (Withania somnifera) on VO2max: a systematic review and meta-analysis. Nutrients. 2020 Apr;12(4):1119. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Adaptogenic Herb, Ashwagandha, and its Effects on Endurance Performance content media
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Ryan Eckert, MS, CSCS
Jan 31, 2022
In The VO2 Max Forum
Injuries Among Triathletes Injuries are unfortunately relatively common among endurance athletes. However, the unique demands of triathlon place a potentially greater risk of injury on athletes competing in the sport. Prior studies have found a wide range of injury rates among triathletes, ranging from 37-91% of athletes (1). The wide range is likely due to a myriad of factors, including different lengths of studies, the training status of individuals followed, and the distance race that the athletes included were preparing for. Nonetheless, the rate of injury among triathletes is relatively high, and so identifying the traits of characteristics associated with injury is an important first step in being able to mitigate the risk of injury among triathletes. A recent study published by Kienstra and colleagues aimed to do just this (1). Prior studies have focused a lot on identifying relationships between training-related factors (training intensity, training volume, training frequency) and injury risk. However, Kienstra and colleagues aimed to identify the relationship between training factors as well as lifestyle factors and injury risk. Let’s take a look at what they found in the next section. Training, Injury, and Lifestyle Characteristics of Recreational Triathletes Authors in this study administered a survey assessing training and other lifestyle characteristics (specific dietary or nutrition strategies, supplement use, medical history) to 34 recreational triathletes in the Miami, Florida area (mean age = 47.6 years; 33% female). Reported Injuries Authors found that 79% identified at least one current area of pain, with the lower extremity being the most common site of injury (72% of all pain and injuries reported). The leg accounted for 17% of all injuries while the hip, knee, and foot accounted for 16% of reported injuries each. Finally, the back, neck, and shoulder accounted for 6%, 7%, and 15% of reported injuries, respectively. Training Characteristics and Injury Athletes who trained more than 12 hours/week had an average of 3.3 injury sites while athletes training less than 12 hours/week had an average of 2.3 injury sites. Other Training Characteristics Only 56% of athletes reported engaging in strength training and only 15% reported engaging in some form of yoga or Pilates. Most athletes (65%) trained under the guidance of a coach. The average training volume per week across all athletes was 11.8 hours/week (range = 4 to 35 hours/week). Athletes planning to race half-distance events or longer averaged 12.6 hours/week of training whereas those planning on racing short-distance triathlons (sprint or Olympic) averaged 10.8 hours/week of training. Nutrition and Supplement Characteristics A total of 65% of athletes reported using some form of supplement or vitamin, with multivitamin use (47%) being the most common, followed by a specific vitamin supplement (30%), a protein supplement (26%), a calcium supplement (15%), a fish oil supplement (15%), and an iron supplement (9%). Most athletes reported no dietary restrictions; however, 15% followed a gluten-free diet, 15% reported a lactose-free diet, 9% a vegetarian diet, and 6% a vegan diet. Every single athlete following a gluten-free, vegan, and vegetarian diet reported at least one injury, whereas 80% of those following a lactose-free diet reported at least one injury. Other Lifestyle Characteristics Among the 34 athletes included in the study, 16 completed the survey questions regarding sleep. A total of 63% of these athletes reported sleeping 6 hours or less per night and nobody reported sleeping more than 9 hours per night. What to Make of All This? Despite the vast majority of triathletes reporting at least one injury, this number might be slightly biased as 9/24 participants were recruited directly from a Miami-based sports medicine clinic, potential inflating the likelihood of injuries among the total sample. Nonetheless, the rate of injury is still high among the triathletes included in this study. The three factors that really stood out to me when sorting through the data were the following: Those training >12 hours/week were more likely to experience injury than those training <12 hours/week. This demonstrates the positive relationship between training volume and injury risk, of which injury risk goes up as training volume goes up; this has been demonstrated among other endurance athletes as well, particularly among runners and long-distance triathletes (1). Only 58% of all triathletes reported engaging in strength training. This is alarming and demonstrates the need for more triathletes to engage in regular strength training as strength training has been well-documented in reducing the risk of overuse and sports-related injuries (2). Among the 16 triathletes that responded regarding their sleeping habits, 63% reported 6 hours/night or less and nobody reported sleeping 9 hours/night or more. This is HUGELY alarming as research demonstrates that nightly sleep durations of less than or equal to 7 hours/night for prolonged periods of time is associated with a 1.7x greater risk of musculoskeletal injury among athletes (3). The important thing to note about these three characteristics above is that they are all modifiable. In other words, these characteristics and behaviors can be improved/changed. Based on the evidence we currently have, I would argue that increasing sleep quantity to >7 hours/night and increasing the proportion of athletes engaging in regular strength training would likely reduce the prevalence of injury among this small sample of recreational triathletes. There is some research linking increased training volume with increased injury risk. For the average recreational triathlete that is usually unable to engage in extreme amounts of training like professionals/elites often engage in, however, the bigger problem is likely what happens around training and not the training volume itself. Triathletes, and endurance athletes more broadly, can lead very busy lives outside of a very demanding sport in triathlon. They quite often have families, full-time jobs, or schooling in addition to part-time jobs. The business of life outside of an already very demanding sport can lead to what is seen in the sample included within this study, chronically poor sleep habits and a lack of athletes engaging in strength training. There are other lifestyle factors contributing to risk of injury as well, including nutrition, however, I quite often see athletes sleeping too little and not engaging in regular strength training individualized for them as an endurance athlete. I would argue that these two characteristics alone account for far too many injuries among recreational triathletes that may otherwise be preventable. Conclusions It is not necessarily shocking to hear of the relatively high prevalence of injury in this small sample of recreational triathletes. I think the most important take-home message from this study for triathletes is to prioritize optimal recovery through good sleeping habits (aiming for at least 7-8 hours of sleep each night) and engaging in a safe, progressive, and individualized strength training to improve overall strength and reduce the risk of injuries. These two lifestyle habits will go a long way in keeping athletes healthy and performing at their best. If you want to learn more about sleep, click here. If you want to learn more about strength training, click here and here. References: Kienstra CM, Cade WH, Best TM. Training, injury, and lifestyle characteristics of recreational triathletes. Current sports medicine reports. 2021 Feb 1;20(2):87-91. Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. British journal of sports medicine. 2014 Jun 1;48(11):871-7. Huang K, Ihm J. Sleep and injury risk. Current sports medicine reports. 2021 Jun 1;20(6):286-90. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Training and Lifestyle Characteristics and Their Relation to Injury Rates Among Recreational Triathletes content media
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Ryan Eckert, MS, CSCS
Jan 03, 2022
In The VO2 Max Forum
What is the rationale behind cold-water immersion to enhance endurance adaptations? I have written previously about the science surrounding the use of cold-water immersion (CWI) and other forms of cold therapies on recovery in athletes. However, another recently popularized use of CWI is to help enhance the long-term adaptation response to and performance of endurance exercise. In other words, CWI done after an endurance training session is reportedly being used to help improve the adaptive response to endurance training and long-term performance. But, does this really work? What is the evidence to support it? Before I dive into the evidence, let’s discuss briefly the rationale behind this theory. A single endurance training session elicits a massive molecular and biochemical response from your body, known as a hormetic response. The short-term stress, and the associated molecular and biochemical responses of a single endurance session results in a temporary reduction in performance, but the adaptive response to repeated short-term stresses ultimately yields a positive net improvement in function and performance. Figure 1 below represents how long-term adaptation to endurance training takes place: It is thought that CWI after endurance exercise helps to augment this process above, specifically at the molecular and biochemical level during the short-term stress response to a single exercise session. For example, research has shown that CWI following a single bout of endurance exercise increases the protein content of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (or PGC-1aplha for short) to a greater extent than just endurance exercise alone (1,3,4). This is one of the molecular responses to endurance training, an increased PGC-1aplha concentration in the muscle, that leads to increased mitochondrial biogenesis (the formation of new mitochondria). This research has gotten some thinking that maybe CWI after endurance exercise can actually enhance the adaptation response to chronic endurance training. However, it is important to know that there is a big difference between what happens initially after a single exercise session and what happens long-term after repeated exercise sessions. In other words, just because CWI after a single exercise session increases PGC-1alpha content of skeletal muscle, one cannot then assume that this will certainly lead to greater mitochondrial content, and therefore greater endurance adaptations, in the long-term. Why? Because the adaptive responses to endurance exercise are insanely complex, and there are literally thousands of molecular and biochemical responses that ensue from a single exercise session. The long-term adaptation process is even more complex as it takes into account these thousands of molecular and biochemical responses to a single session and multiplies it over days, weeks, and months. To truly know whether or not CWI after endurance exercise helps augment long-term adaptation, we need to look at research that has studied the long-term effects of CWI on endurance adaptation and performance. Let’s take a look at this research next. What Does the Research Say Regarding Cold-Water Immersion on Endurance Adaptation and Performance? Broatch and colleagues (2) published a systematic review of the literature in 2018 in which they aimed to examine the influence that CWI had on adaptive responses to exercise across both endurance exercise and strength exercise. For the purposes of this write-up, I’m only focusing on their findings as they relate to endurance exercise, but I would recommend you check this review paper out if you want more detail as it pertains to strength exercise. Essentially, the authors found that while some studies do show short-term increases in markers of mitochondrial biogenesis (e.g., increased PGC-1alpha among other markers), there was no long-term changes from regular CWI post-exercise over time. In other words, although CWI immediately after endurance training might elicit or augment increases in certain molecular pathways important for long-term training adaptations, this doesn’t appear to actually play out with increased endurance training adaptation in the long-run, including a lack of increase in mitochondrial proteins, which one would expect to see if CWI helped augment greater changes in endurance adaptation compared to exercise alone. Malta and colleagues (5) published a slightly more recent systematic review and meta-analysis in 2021 that aimed to examine the influence of CWI on actual performance outcomes across both strength training and endurance exercise; however, I will again only focus on the endurance findings herein. I do recommend you read this paper as well though if you want to deepen your understanding of CWI on exercise performance. Interestingly, and in line with the prior 2018 systematic review that found no beneficial effects of CWI on adaptive responses to chronic endurance exercise, this 2021 review found that CWI had no significant negative or positive effect on markers of endurance performance (cycling time-trial mean power, maximal aerobic power, and cycling time trial performance). The findings from these two papers taken together demonstrate no real effect of chronic CWI post-endurance exercise on adaptive responses nor endurance performance. The research that has been done so far is not without its limitations, however, namely the length of cold exposure time possibly being insufficient to elicit long-term adaptive effects or performance improvements. The typical CWI protocols across all studies included within these papers typically consists of immersing oneself in water at 40-50 degrees F for 10-20 minutes after exercise for 3-7 weeks in length. Broatch and colleagues (2) noted that extremely long cold air exposure in the order of multiple months at a time in animals has elicited long-term increases in mitochondrial proteins, which would mark improvements in endurance adaptations. However, the exposure time each day is likely far longer than what any normal athlete would expose themselves to, which has been upwards of 24 hours/day of cold exposure in the animals studied. Malta and colleagues (5) also mentioned that it is largely unknown if longer CWI exposure per session would result in more favorable findings on long-term performance outcomes. There might be an optimal window of time that is longer than current protocols (e.g., >20 minutes at a time) or colder than current protocols (e.g., <40 degrees F) that does indeed work. It is also possible that longer-term studies (i.e., longer than 7 weeks) are needed to see endurance adaptations or performance benefits take place from CWI. Finally, it could also be possible that extremely cold air exposure has the potential to augment endurance adaptations and performance as one can expose themself to far colder temperatures than they otherwise could with cold water. However, these types of studies have not been done yet. Further research is needed to answer these questions. Conclusions Broadly, the use of CWI is not recommended as a means of enhancing long-term endurance training adaptations and performance outcomes. Despite promising research showing short-term increases in markers of endurance adaptation, these short-term increases do not seem to materialize into long-term adaptations indicative of enhanced endurance adaptation nor actual performance improvements. The use of CWI to enhance recovery after training is another popular use of this modality. The evidence is very mixed on whether CWI works to enhance the recovery process between hard training sessions as well (2). However, there does not seem to be any harm to doing CWI post-endurance exercise, both in terms of its short-term effects and its long-term effects, so if you already use CWI after exercise and you enjoy it, there would be no reason to discontinue. Go on with it at your pleasure, or discomfort, depending on how you view CWI. Personally, I enjoy short bouts of cold showers each day for reasons other than recovery or the possibility of enhanced endurance adaptation. I also like to pair up infrared sauna sessions with cold showers immediately afterwards for contrast therapy. I enjoy the invigorating sensation I get after a few minutes of cold exposure, so I’ll continue doing this with the knowledge that it is likely not helping my performance nor hindering it. References: Allan, R., Sharples, A. P., Close, G. L., Drust, B., Shepherd, S. O., Dutton, J., ... & Gregson, W. (2017). Postexercise cold water immersion modulates skeletal muscle PGC-1α mRNA expression in immersed and nonimmersed limbs: evidence of systemic regulation. Journal of Applied Physiology, 123(2), 451-459. Broatch, J. R., Petersen, A., & Bishop, D. J. (2018). The influence of post-exercise cold-water immersion on adaptive responses to exercise: a review of the literature. Sports Medicine, 48(6), 1369-1387. Ihsan, M., Watson, G., Choo, H. C., Lewandowski, P., Papazzo, A., Cameron-Smith, D., & Abbiss, C. R. (2014). Postexercise muscle cooling enhances gene expression of PGC-1. Med Sci Sports Exerc, 46(10), 1900-1907. Joo, C. H., Allan, R., Drust, B., Close, G. L., Jeong, T. S., Bartlett, J. D., ... & Gregson, W. (2016). Passive and post-exercise cold-water immersion augments PGC-1α and VEGF expression in human skeletal muscle. European journal of applied physiology, 116(11), 2315-2326. Malta, E. S., Dutra, Y. M., Broatch, J. R., Bishop, D. J., & Zagatto, A. M. (2021). The effects of regular cold-water immersion use on training-induced changes in strength and endurance performance: a systematic review with meta-analysis. Sports Medicine, 51(1), 161-174. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Can Cold-Water Immersion Enhance Endurance Training Adaptation and Performance? content media
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Ryan Eckert, MS, CSCS
Dec 01, 2021
In The VO2 Max Forum
Isn’t Strength Training just for Weight-Lifting and Strength/Power-Based Athletes? Nope! I have written a lot on strength training in previous posts of mine, but a recent study has me excited as it is one of the first studies to take a look at how a long-term strength training program impacts exercise economy specifically in triathletes. There have been numerous studies done showing that exercise economy is improved in cyclists and runners that undertake a regular, heavy-load strength-training program (1); however, this research has largely been done in single-sport athletes. Son, in theory, the effects of strength training on exercise economy in triathletes is not precisely known as this research has not been done. It is no surprise that triathlon is different from its’ single-sport counterparts that undertake stand-alone swimming, cycling, and running. One of the biggest differences is that each discipline of triathlon has a cumulative fatiguing effect on the subsequent discipline, reducing exercise economy in the process. For example, runners participating in a stand-alone marathon undertake this endeavor fresh, whereas in triathlon, an Ironman-distance triathlete would undertake the marathon portion of the event carrying significant fatigue from the swim and bike, and these previous two disciplines have a negative impact on running economy compared to a marathon that was done when fresh and not preceded by a swim and bike. Strength training, however, is known to improve exercise economy, particularly in cycling and running (1). Exercise economy is typically defined as the energetic cost (oxygen consumption) associated with a sustained power or pace output (2). Exercise economy is thought to be improved through strength training by the following mechanisms: 1. Improved ability to store and release elastic energy from increased musculotendinous stiffness a. This primarily impacts running which is a sport that requires the utilization of storing and releasing elastic energy with every stride 2. Improved rate of force development (RFD) of musculature a. This is primarily a neural improvement of the musculature’s ability to generate force quickly 3. Increased maximal strength a. This allows for a greater recruitment of less fatigable, type 1 slow-twitch muscle fibers during submaximal cycling and running These improvements described above ultimately improve exercise economy, which means a reduction in the oxygen demand during submaximal exercise, thereby improving performance. Exercise economy has been well-established as a valid marker or predictor of endurance performance, with a greater exercise economy predicting better endurance performance (1,2). However, no research has been done to date examining strength training’s impact on triathletes during successive swimming, cycling, and running. Luckin-Baldwin and colleagues (2) attempted to change this by conducting the first study of its kind in which strength training and its impact on exercise economy was examined in triathletes during a simulated long-distance triathlon. Let’s take a look at this study and the findings. Strength Training for Triathletes This study took 25 well-trained, long-distance triathletes and randomly assigned them to 26 weeks of concurrent strength training and endurance training (n=14) or just endurance training (n=11). The concurrent strength/endurance group performed 26 weeks of progressive strength training in addition to their usual endurance training, whereas the endurance only group simply performed their usual endurance training. The strength training program consisted of two sessions per week, with weeks 0-12 consisting of moderate loads (8-12 repetitions @ <75% of one rep maximum) and weeks 14-26 consisting of heavy loads (1-6 repetitions @ >85% one rep maximum). There was a two-week break in the middle of the strength training program to allow recovery. All study participants completed a simulated triathlon consisting of a 1500-meter swim, a 60-minute cycle, and a 20-minute run at weeks 0, 14, and 26 while researchers collected exercise economy data and other measures. The concurrent strength/endurance group saw improvements in maximum strength over the entire 26 weeks as well as improvements in cycling economy at week 14 and running economy at week 26 with no changes in total body mass. The endurance-only group did not see any improvements in cycling nor running economy at any time points. These findings are about what we would expect given the published literature documenting the beneficial effects of strength training on cyclists and runners, but this is the first study of its kind to demonstrate these improvements in triathletes. Interestingly, cycling economy improved after only 12 weeks of moderate-load strength training while running economy only improved after the heavy-load strength training phase at week 26. Typically, very heavy loads and/or explosive strength training elicit improvements in exercise economy, but there has been some research showing that moderate loads can improve exercise economy during cycling, and this might explain why these improvements in exercise economy were only seen in cycling at week 14 whereas running economy didn’t improve until week 26 (2). Another important finding was that these improvements in maximum strength and exercise economy occurred without an increase in body weight. This is important as some endurance athletes worry that engaging in strength training will lead to an increase in muscle mass, and therefore an increase in total body mass, and lead to a reduction in endurance performance. However, this is typically not the case as it is pretty well-documented that concurrent endurance and strength exercise prioritizes endurance adaptation over muscle hypertrophy adaptations. Endurance exercise is known to inhibit intracellular signaling pathways important for muscle protein synthesis and growth, which likely explains why concurrent endurance and strength training typically does not yield significant increases in muscle size, particularly in endurance athletes that engage in large amounts of endurance training (2). You might be wondering why swimming economy was not improved? Well, first of all, it was not measured, but strength training is also not known to typically improve swimming economy even though strength training for swimmers is still recommended. Finally, this study did not measure objective performance outcomes, so it was not possible to extrapolate the improvements in exercise economy to any improvements in objective performance during the simulated triathlon. However, exercise economy is such a strong predictor of endurance performance, that it is very likely that improvements in exercise economy would translate to some form of measurable objective performance during a triathlon (1). However, further work will of course be needed to demonstrate this. Conclusions While the general findings of this study are not groundbreaking in and of themselves, these findings are the first of their kind in triathletes specifically. It is exciting to see that a concurrent strength/endurance program can positively impact cycling and running economy while improving maximum strength in triathletes without an increase in body mass. The findings add further justification for the recommendation for triathletes to engage in long-term strength training, not only for general injury prevention, but for improved exercise economy. References: 1. Bazyler CD, Abbott HA, Bellon CR, Taber CB, Stone MH. Strength training for endurance athletes: theory to practice. Strength & Conditioning Journal. 2015 Apr 1;37(2):1-2. 2. Luckin-Baldwin KM, Badenhorst CE, Cripps AJ, Landers GJ, Merrells RJ, Bulsara MK, Hoyne GF. Strength Training Improves Exercise Economy in Triathletes During a Simulated Triathlon. International Journal of Sports Physiology and Performance. 2021 Feb 11;16(5):663-73. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Strength Training Improves Exercise Economy in Long-Distance Triathletes content media
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Ryan Eckert, MS, CSCS
Nov 02, 2021
In The VO2 Max Forum
What is Iron? Iron is a critical micronutrient that is needed in the diet since the body cannot produce iron on its own. Iron is important and required for numerous processes in the body, ranging from proper immune cell function to the formation of red blood cells. Likely a few of the most important functions of iron for endurance athletes are its role in oxygen transport via hemoglobin and myoglobin as well as its role in oxidative production of adenosine triphosphate (ATP) within the electron transport chain (3). Therefore, a compromised storage of iron could potentially disrupt the formation of red blood cells and the ability to generate ATP via oxidative metabolism, both of which could impair endurance performance capacity. Iron deficiency is one of the most common deficiencies in the world, and so rightfully so it tends to be a micronutrient that gets a lot of attention in general. However, iron deficiency is also one of the more common micronutrient deficiencies among athletic populations, particularly endurance athletes and team-based athletes. It is estimated that ~15-35% of female athletes and ~3-11% of male athletes are deficient in iron; however, some smaller studies suggest even higher numbers than these (3). The rates of iron deficiency are much higher in athletes than they are in non-athletes as well (3). What makes athletes more likely to experience iron deficiency? It has been proposed that any one, or all, of the factors below increase the likelihood of athletes being at greater risk of iron deficiency compared to non-athletes (3): Hemolysis (breakdown of red blood cells) exacerbated by ground-contact forces during running Post-exercise inflammatory responses which leads to greater post-exercise interlekin-6 (IL-6) concentration, which increases hepcidin concentration, and hepcidin is the master regulating hormone of iron, with higher hepcidin leading to reduced iron absorption from the gut Greater potential for gastro-intestinal bleeding Potential for iron loss through sweat Greater breakdown and production of red blood cells due to adaptations in response to exercise Of note, women also have a higher need for iron, and therefore a greater likelihood of becoming deficient, due to the loss of blood and iron associated with their menstrual cycle. This is of course not unique to only female athletes, however. In regards to iron deficiency, it important to note, that like other micronutrient deficiencies, there are differing stages of iron deficiency ranging from initial less severe stages that may not exhibit any overt symptoms all the way to the most severe stage in which there are significant negative consequences and symptomatology. Iron is stored in the body as ferretin or hemosiderin, and these stores are usually what is depleted initially, with actual hemoglobin and red blood cell production affected in later stages of deficiency when iron stores get severely depleted. For iron deficiency in athletes, the following three stages of deficiency have been proposed: Stage 1: iron deficiency (ID): iron stores in the bone marrow, liver and spleen are depleted (ferritin < 35 μg/L, Hb > 115 g/L, transferrin saturation > 16%). Stage 2: iron-deficient non-anaemia (IDNA): erythropoiesis diminishes as the iron supply to the erythroid marrow is reduced (ferritin < 20 μg/L, Hb > 115 g/L, transferrin saturation < 16%). Stage 3: iron-deficient anaemia (IDA): Hb production falls, resulting in anaemia (ferritin < 12 μg/L, Hb < 115 g/L, transferrin saturation < 16%). Most people reading this might think that iron deficiency is really only a problem if anemia (low red blood cell volume and reduced hemoglobin concentration) is present. While it is true that low red blood cell volume and iron-deficiency anemia has well-documented negative consequences on athletic performance, some research also might suggest a reduction in performance from iron-deficiency non-anemia, likely due to impaired oxidative metabolism in the absence of reduced red blood cell volume (3). Therefore, catching iron deficiency at any stage is critical, not just for general health and well-being, but also for athletic performance. This is why it is usually recommended for endurance athletes to have iron status checked annually, or even biannually or quarterly if you have had evidence of impaired iron status previously (3). What Happens if Iron Status is Compromised? Firstly, it should be mentioned that an athlete should never guess when it comes to iron status. If an athlete wants to know what their iron status is, whether it is due to simple curiosity or because they experience some potential symptoms indicating iron deficiency (e.g., lethargy, weakness, fatigue, reduced endurance performance, etc.), they should have their iron levels tested by your primary care physician. There are also micronutrient testing options that one can get as well, and these don’t necessarily always have to be ordered through one’s primary care physician. Regardless of how the testing is done, so long as it is an accurate test, it is imperative that an athlete gets tested before manipulating iron intake as supplementing with iron when one is not deficient has no benefit. The benefits from increasing iron intake through food or supplementation typically only come when someone is deficient. So, let’s say an athlete gets their iron status tested and they do indeed have a deficiency. How is this normally handled? Typically, the first approach is to increase iron in the diet (fortified cereals, fish, meat, poultry, green leafy vegetables, etc.) (3). A change in diet to promote increased iron intake may also be done in conjunction with consuming foods that also increase the absorbability of iron, such as vitamin C or consuming heme iron foods (meat, fish, poultry) as opposed to non-heme sources (vegetables, beans/legumes, etc.). The second approach is to supplement with an oral supplement (3). Oral supplements can be elemental iron sources such as ferrous sulfate, or they could be chelated iron sources such as ferrous bisglycenate. It is important to mention here that chelated forms of iron may be advantageous to elemental iron when it comes to supplementation as chelated forms of iron can typically be taken in lower doses due to enhanced absorbability (1,2). Chelated forms of iron are also typically better tolerated compared to elemental iron, which is commonly associated with gastrointestinal upset and nausea (1,2). Finally, the third approach is to administer iron via an intramuscular shot or intravenous drip (3). However, this approach is usually only reserved for cases of severe iron-deficiency anemia in which rapid increases in iron stores are desired (3). When an athlete does have a compromised iron status, including milder deficiencies such as iron deficiency or iron deficiency without anemia, research has shown that endurance performance can possibly be improved when supplementing with iron (3). With the most severe cases of iron deficiency anemia, performance is likely severely compromised, and so supplementing with iron will almost surely improve performance as iron stores and hemoglobin status is improved (3). Conclusions To conclude, iron is an important and critical micronutrient for general health, but also for athletes, particularly endurance athletes. Iron deficiency is much more common among athletes than non-athletes due to various factors, and correction of iron deficiency is likely to have benefits on overall performance, particularly among those with severe iron deficiency anemia. Iron status can be improved through increasing oral iron intake (diet, supplementation) or via intramuscular shots or intravenous fluid. However, testing for iron deficiency should be done to confirm an actual iron deficiency before attempting to increase iron intake. It is, of course, good practice to regularly consume foods with iron with or without testing as iron is required in our diets, but supplementing with iron via oral supplementation or intramuscular shots or intravenous fluids should not be done if iron deficiency is not present due to the increased health risk of too much iron and the lack of performance benefit by athletes increasing iron intake without the presence of iron deficiency. If you are looking to learn more about iron and its considerations specifically for athletes, I highly recommend reading reference #3 in the reference list below as it is a 2019 review on the topic. On a side note, if you are looking for an iron supplement to help correct an identified deficiency, I personally love the Athlete’s Iron from MOXiLIFE as it is a highly absorbable and gut-friendly chelated form of iron. As an added benefit, it also contains some gut-friendly prebiotics. References: 1. Ashmead. H.D., Guaiandro. S.F.M., and Same. J.J. 1997. Increases In hemoglobin and ferritin resulting from consumption of food containing ferrous amino acid chelate (ferrochel) versus ferrous sulfate. In Trace Elements in Man and Animals - 9: Proceedings of the Ninth International Symposium on Trace Elements in Man and Animals. Edited by P.W.F. Fischer. M.R. L’Abbe. K.A. Cockell, and R.S. Gibson. NRC Research Press. Ottowa. Canada. Pp. 284-285. 2. Ferrari P, Nicolini A, Manca ML, Rossi G, Anselmi L, Conte M, Carpi A, Bonino F. Treatment of mild non-chemotherapy-induced iron deficiency anemia in cancer patients: comparison between oral ferrous bisglycinate chelate and ferrous sulfate. Biomedicine & Pharmacotherapy. 2012 Sep 1;66(6):414-8. 3. Sim M, Garvican-Lewis LA, Cox GR, Govus A, McKay AK, Stellingwerff T, Peeling P. Iron considerations for the athlete: a narrative review. European journal of applied physiology. 2019 Jul;119(7):1463-78. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Iron Intake Among Endurance Athletes content media
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Ryan Eckert, MS, CSCS
Sep 30, 2021
In The VO2 Max Forum
What are Omega-3 Fatty Acids? Omega-3 fatty acids consist of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha linoleic acid (ALA). EPA and DHA are the fatty acids primarily found in fatty fish, whereas ALA is typically found in plant oils, nuts, and seeds (1). These three fatty acids are considered essential as the body does not produce them in sufficient quantities. Therefore, these fatty acids must be obtained in the diet. ALA can be converted to EPA and DHA in the body, but the conversion rate is extremely low (3-10%) in humans partially due to typical western diets consisting of too much Omega-6 fatty acids (1). The lack of EPA and DHA consumption in typical western diets as well as the higher Omega-6 intakes throws off the ratio of omega-3 to omega-6 fatty acids that would be considered ideal for optimal health (1). It is for this reason that omega-3 supplementation, with a particular emphasis on EPA and DHA, has become more and more popular in recent decades. In fact, omega-3 supplementation has a large body of evidence to support its health benefits, particularly for improving cardiovascular health and reducing the risk of cardiovascular disease and cardiovascular-related mortality from stroke and heart attacks (2). Omega-3 fatty acids have a vast array of other health benefits too, however, including beneficial impacts on nervous system function and immune function. Athletes have become interested in omega-3 fatty acids due to the beneficial effects of these compounds on inflammation. Dietary omega-3 fatty acid consumption has the potential to reduce inflammation, which is proposed as a way to enhance recovery from strenuous exercise (1). I became interested in the potential benefits of omega-3 fatty acids for endurance athletes after I started working to improve my diet. I have recently transformed my diet to reduce my intake of added sugars and processed foods while also increasing my consumption of fruits, vegetables, nuts, seeds, and other nutrient-dense foods. I went as far as getting a comprehensive micronutrient panel done so that I could further optimize my diet to eliminate micronutrient deficiencies. I don’t regularly consume fatty fish, so I knew I was likely not consuming enough omega-3 fatty acids in my diet. This was when I turned to a high-quality fish oil supplement, mainly for general health benefits. However, then I started looking at the potential performance benefits that omega-3 fatty acids have for endurance athletes. I will do my best to summarize what I found in the section below. What Is the Impact of Omega-3 Fatty Acid Supplementation on Endurance Performance? There was a really nice review article published in Research in Sports Medicine by Dr. Philpott and colleagues (1) discussing the applications of omega-3 fatty acid supplementation for sports performance. One of the subsections of this paper was specifically focused on the research surrounding omega-3 fatty acid supplementation for endurance sports performance. There is some research and limited evidence to suggest that omega-3 fatty acid supplementation may enhance mitochondrial biogenesis (the formation of more mitochondria), which would of course be particularly beneficial to endurance athletes as the more mitochondria would mean a greater capacity to utilize oxygen to breakdown glycolysis by-products and fat for fuel during exercise. However, this research was conducted in rodents and obese individuals, so the direct application to endurance athletes is lacking at this point. There is a bit more evidence, however, demonstrating that omega-3 fatty acid supplementation can reduce the oxygen cost of submaximal endurance exercise as well as reduce submaximal exercise heart rate due to the beneficial effects that EPA and DHA have on stroke volume and muscle cell insulin sensitivity. There is actually some research in cyclists demonstrating this, however, these reductions in oxygen cost and heart rate did not translate into objective cycling performance improvements in time trials. So, despite potential physiological changes from omega-3 fatty acid supplementation in endurance athletes, it has yet to be demonstrated that this translates into real-world performance improvement. Finally, there is the potential for omega-3 fatty acid supplementation to reduce the risk of upper respiratory tract infection (URTI) among endurance athletes due to the beneficial immunomodulatory effects of omega-3 fatty acids. Endurance athletes can be at a greater risk of URTIs, especially during periods of heavy training load. Therefore, if omega-3 fatty acid supplementation can reduce this risk and keep endurance athletes healthy with fewer bouts of illness, then this would theoretically have a positive downstream effect on performance as athletes would not miss training as often due to illness. However, again, there is limited data that directly demonstrates fewer bouts of illness when endurance athletes consume omega-3 fatty acids either from food or via supplementation. Conclusions As you can tell from reading the above, most of this research involving omega-3 fatty acid supplementation in endurance athletes is still very limited and inconclusive due to such limited studies being done. However, my personal opinion is as follows: If you do not regularly consume foods rich in omega-3 fatty acids, either starting to consume foods high in omega-3 fatty acids or taking a high-quality omega-3 fatty acid supplement is not likely going to impair endurance performance and can only improve your overall health. There is, of course, the potential for it to improve your endurance performance via the mechanisms outlined above. However, even if omega-3 fatty acid intake does not translate to objective performance enhancement, it will still likely improve your health as there are myriad health benefits to be had from regular intakes of omega-3 fatty acids in the range of 1-2 grams/day of EPA/DHA (1,2). This could certainly be something to consider if you do not consume enough omega-3 fatty acids in your diet on a regular basis. References: Philpott JD, Witard OC, Galloway SDR. Applications of omega-3 polyunsaturated fatty acid supplementation for sport performance. Res Sports Med. 2019 Apr-Jun;27(2):219-237. doi: 10.1080/15438627.2018.1550401. Epub 2018 Nov 28. PMID: 30484702. Bernasconi AA, Wiest MM, Lavie CJ, Milani RV, Laukkanen JA. Effect of Omega-3 Dosage on Cardiovascular Outcomes: An Updated Meta-Analysis and Meta-Regression of Interventional Trials. Mayo Clin Proc. 2021 Feb;96(2):304-313. doi: 10.1016/j.mayocp.2020.08.034. Epub 2020 Sep 17. PMID: 32951855. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
The Effects of Omega-3 Fatty Acid Supplementation on Endurance Performance content media
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Ryan Eckert, MS, CSCS
Sep 07, 2021
In The VO2 Max Forum
The Debate on Dehydration and Endurance Performance? It is a pretty commonly held belief among athletes, coaches, and researchers alike in the endurance space that dehydration negatively affects endurance performance. However, despite this widely held belief, a belief that does have substantial evidence to back it up by the way, many researchers and coaches still debate this belief and argue that dehydration might not negatively impact endurance performance. This topic is one I am keenly interested in as I have had some personal experience with dehydration and it affecting my endurance performance. I could not imagine being able to perform my best without having an adequate hydration strategy during a race. I have seen the deleterious consequences for both myself and athletes I coach when a proper hydration plan is not adhered to, particularly in long-distance races like Ironman and Ironman 70.3 events. I had always believed, based on what I learned in school, what I read in the research, and what I read in sports nutrition textbooks, that dehydration had a negative impact on performance and endurance athletes should avoid huge losses in body water during competition. So, I was shocked to see that some coaches and researchers tried to argue against this idea! This shock has led me to dive a bit more into the research supporting and refuting the notion that dehydration impacts performance, and I have come across a recent article (1) in which the authors discuss some of the potential methodological considerations of dehydration research that might impact the interpretations and conclusions drawn from it. The aim of this paper was essentially to critically analyze the methods of seminal work in the area of dehydration research and endurance performance in order to have a better understanding of why some might think dehydration negatively affects performance and why others dismiss this notion as false. Because, when you do dive into the research, some shows that dehydration impairs endurance performance while some shows the opposite. So, does dehydration really affect endurance performance like most of us have been taught? This is an incredibly important question to answer as it influences how athletes and coaches approach hydration strategies and plans during training and in competition. After all, many endurance athletes are very particular about finding an individualized hydration strategy in order to avoid a significant loss of body water and to maintain performance. Let’s discuss this recent paper to see what the authors found. What Is the Impact of Dehydration on Performance, In Theory? Dehydration, particularly dehydration of greater than 2-3% of body weight, has long been thought to impair endurance performance. It is thought to negatively impact performance primarily through a reduction in blood plasma volume and a greater competing interest between the muscle and the skin for oxygen-rich blood flow. As the body warms up, one of the primary mechanisms by which athletes cool themselves is through sweating. Blood flow to the skin is increased and sweating dissipates heat as the water moves from the blood to the skin and finally evaporates from the skin. As more and more body water is lost, this reduces the overall plasma volume of our blood, which has a negative impact on cardiac output during exercise, essentially making the heart have to beat faster to keep up with the oxygen demands of exercise. Additionally, as blood is shunted to the skin to help with sweating, less blood gets diverted to the muscles, thereby placing an overall greater demand on the heart to keep up with the increasing demand for blood to the muscles and to the skin. These two factors, among some others not mentioned here, greatly impair endurance performance output as heart rate and perceived exertion rise in this situation. It is for these reasons above that endurance performance is usually optimized in very cool conditions and when an athlete is well hydrated and has minimal fluid loss. So then, why is it debated that dehydration does NOT have an impact on performance? What Does the Research REALLY Suggest? Like I mentioned earlier, there is conflicting research out there that shows that dehydration does not impair performance in select studies. However, as the authors of a recent 2019 paper point out (1), this research may have some flaws that has caused some coaches or researchers to draw incorrect conclusions. I’ll refer you to read this paper in its entirety to get the exact specifics of these potential methodological flaws, but essentially participant blinding to hydration status, the route of rehydration of study participants, and the methods of dehydrating participants may have confounded the outcomes in these studies showing no impairment of dehydration on endurance performance. Other studies that do not have these potential methodological flaws do in fact consistently demonstrate that dehydration, particularly dehydration of greater than 2-3%, impairs endurance performance. This is important, as it eludes to the fact that hydration status does seem to matter when it comes to maintaining optimal endurance performance. The authors point out some areas in which more research is needed. However, the research does seem to be pretty clear that dehydration of greater than 2-3% body weight impairs performance in most athletes and that hydration strategies/plans should be in place to avoid body mass losses of this magnitude during prolonged endurance activity if optimal performance is the desired outcome, such as in a race or competition. Conclusions So, it might be that the hot debate amongst professionals as it relates to dehydration and performance shouldn’t be quite as hot as it is given what the authors of a recent 2019 paper discussed (1). Dehydration does seem to impair endurance performance and hydration strategies aiming to minimize body weight loss to less than 2-3% should likely be a goal for all endurance athletes during competition, particularly prolonged endurance competition (i.e., >90 minutes) where hydration status starts to play a larger role in maintenance of performance. It would also not be correct to completely dismiss those arguing that dehydration plays little role in impairing endurance performance as more and more research is indeed needed. It is important to consider their argument and use this to investigate the role of hydration status on endurance performance even further so that we have clearer cut findings. However, if you come across a book, article, or professional in the field that is adamant in arguing that hydration does not matter very much and that we should all ‘just drink to thirst” in prolonged endurance competitions, I would take this with a very large grain of salt as the research that backs up this claim is very shaky and fragile to say the least. What is the main take-home from this brief write-up? Keep focusing on dialing in a hydration strategy that works for you, with the ultimate goal being to minimize fluid losses in competition if optimal performance is your aim! References: 1. James LJ, Funnell MP, James RM, Mears SA. Does hypohydration really impair endurance performance? Methodological considerations for interpreting hydration research. Sports Medicine. 2019 Dec;49(2):103-14. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Does Dehydration Really Impact Endurance Performance? content media
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Ryan Eckert, MS, CSCS
Aug 02, 2021
In The VO2 Max Forum
What is Cryotherapy? Most athletes have heard of the term “cryotherapy” and usually associate it with the form of whole-body cooling that can be done by entering a freezing cold chamber of air cooled to well below 100 degrees Celsius. Whole-body cryotherapy has been, in part, made more popular in recent years due to its endorsement by professional athletes and celebrities alike in the media as well as different companies and clinic/spas promoting it as a highly beneficial therapy. However, like many recently popularized recovery and therapeutic modalities, popularity does not necessarily mean it is effective. In literal terms, cryotherapy means “the use of extreme cold in surgery or other medical treatment”. As I mentioned previously, however, whole-body cryotherapy in which one enters a chamber of freezing cold air is the form of this therapy that most would be familiar with. Therefore, for the purpose of this article, I will refer to whole-body cryotherapy as, simply, cryotherapy moving forward. Cryotherapy falls under the umbrella of various forms of cold therapy. It has been long postulated that the application of cold to athletes can help in the recovery from strenuous or damage-inducing exercise via various mechanisms. Firstly, cooling causes blood vessels to skin and muscle to constrict (vasoconstriction), thereby leading to a reduced inflammatory response post-exercise (2). Additionally, cold therapy is known to reduce the severity of delayed onset muscle soreness (DOMS) by slowing the neural conductance velocity of sensory neurons, essentially blunting pain responses in the process (1). However, despite these potential mechanisms of cold therapy, it is also postulated that these effects of cold therapy applied post-exercise may actually slow the recovery process or blunt it to some extent (2). The inflammatory response from strenuous exercise is a GOOD thing and is part of the cascade of events that ultimately leads to positive adaptations. This is one reason why incorporating therapies or modalities that are anti-inflammatory (i.e., cold therapy, non-steroidal anti-inflammatory drugs, etc.) after training sessions may be counterproductive. Nonetheless, cold therapies, including cryotherapy, continue to be touted as beneficial recovery strategies for athletes. I have previously written about the science surrounding other cold therapies, particularly ice baths, of which you can read that write-up here. However, cryotherapy is a bit different to ice baths as cryotherapy relies on extremely cold air being applied to the individual as opposed to cold water. Therefore, there could be subtle differences in the physiological recovery outcomes experienced. Let’s discuss what “recovery” means post-exercise next. What Does Optimal Recovery Post-Exercise Even Mean? Answering this question is harder than you might think. At the most basic level, maximizing or enhancing recovery after training sessions would promote positive adaptation while at the same time minimizing the impact of a prior training session on an upcoming training session. In other words, recovery strategies should help you, as an athlete, positively respond to the training session you just did while helping you feel your best for your next training session. At least, this is the general idea or logic. In general, researchers examining the effects of different modalities on recovery usually focus on the following three outcomes: Delayed onset muscle soreness (DOMS) - Soreness is most pronounced, however, after very intense exercise involving significant eccentric loading, so not all exercise will lead to DOMS; the sensation of DOMS is also not related in any way to the effectiveness of an exercise session Physiological work or output characteristics - This might include the recovery of various qualities post-exercise that are specific to the sport or type of athlete being studied, including peak power outputs, jumping capacity, agility tests, VO2 max, lactate threshold, sub maximal endurance, etc. Blood markers of exercise-induced damage or inflammation - This could include lactate or lactate dehydrogenase levels, creatine kinase levels, or inflammatory biomarker levels; these are all markers that would typically be elevated for a few days following strenuous exercise It is difficult for researchers to measure all possible outcomes related to recovery as there are likely an unlimited number of variables that could be measured and tied to recovery in some form or fashion, but these are the three most common ways of looking at recovery outcomes post-exercise. So, keeping these outcomes in mind, let’s dive into the science surrounding the use of cryotherapy, as well as other cold therapies in general, and their effects on recovery after exercise. What Does the Evidence Say Regarding Cryotherapy Use in Athletes? There have been multiple reviews and meta-analyses published in the last decade related to the effects of various cold therapies on recovery outcomes. A somewhat recent meta-analysis from 2015 aimed to examine the impact that cryotherapy had on recovery outcomes as compared to passive control groups (2). This meta-analysis included a total of 36 published studies that included 574 healthy athletes and non-athletes. Across these studies, not all utilized cryotherapy, however. In fact, only two of these studies examined cryotherapy in particular, 28 studies used cold water immersion, and six used different modalities such as a mix of cryotherapy and cold-water immersion or application of ice packs and ice vests. This meta-analysis included studies that looked at the effect of cold therapies on the following outcomes in particular: 1) DOMS, 2) lactate levels, 3) creatine kinase levels, and 4) blood plasma inflammatory cytokines. All of these outcomes were typically assessed 24, 48, 72, and/or 96 hours post-exercise. Major findings from this meta-analysis were as follows: Cold-water immersion demonstrated a significant effect on reducing DOMS at 24, 48, and 96 hours post-exercise; other cold therapies, including cryotherapy, did not have this significant effect. None of the cold therapies demonstrated any significant effect on blood nor muscle lactate levels, creatine kinase levels, nor inflammatory cytokine levels 24, 48, 72, nor 96 hours post-exercise. So, in general, cold therapies, including cryotherapy, did not have much effect on the recovery outcomes assessed in this meta-analysis with the exception of cold-water immersion on DOMS for a few days post-exercise. However, it should be mentioned that this meta-analysis is limited in the sense that it included a primarily male sample (72% male) and a primarily young sample (mean age was 22 years). Additionally, the included studies had an average sample size of 16 participants, but this is the advantage of a meta-analysis in the sense that there is a larger cumulative sample size to work with, increasing the power of the analyses and the ability to detect true effects of cold therapies on recovery outcomes. Finally, this meta-analysis only included two studies that specifically examined cryotherapy in isolation on recovery, so from the perspective of cryotherapy alone, there were fewer studies to draw from when forming conclusions about this specific modality. Conclusions It seems that cold therapies may at best have an impact on DOMS following exercise, but not much effect on other markers of recovery. Additionally, it seemed that cold water immersion was the only effective cold therapy when it came to reducing DOMS post-exercise, with cryotherapy and other cold therapies showing no impact. The findings of this meta-analysis were actually somewhat surprising to me as the research is very conflicting in regards to the effects of cold-water immersion and ice baths on DOMS, with some studies showing benefit and others showing no benefit. Therefore, I was surprised to see that this meta-analysis found cold-water immersion as effective at reducing DOMS. I was also surprised that cryotherapy had no effect on DOMS as I would have thought that it would reduce the sensation of DOMS. It is very important to keep in mind that much of the benefit of any type of cold therapy on recovery could be due to the placebo effect and not an actual effect of the cold therapy itself (2). This effect has been documented with cold therapies, and the effects of cold-water immersion and ice baths on DOMS and other recovery outcomes may come down to participants believing it will help them and so they convince themselves that it actually does. This is an important point to make in general when it comes to many of the recovery tools and modalities that are available today as many of them may have no actual scientific evidence to support their claimed effects, so many of the benefits that individuals report or companies try to sell their products on may be nothing more than placebo effect. So, in regards to cryotherapy specifically, does the evidence back up the hype? No, it definitely does not. However, the research is still limited and it is rapidly evolving. I wouldn’t go so far as to say that it is completely useless as a recovery tool for athletes, and more recent research has started to investigate its use as a recovery tool for injured athletes (1). However, the research certainly isn’t there quite yet to support its effectiveness as a tool to promote recovery in athletes that are training regularly. Additionally, given how expensive a single cryotherapy session can be, I would encourage athletes to utilize other recovery strategies with more evidence to back up their effectiveness. Cold-water immersion, or ice baths, as well as foam rolling are examples of some modalities that have a bit more evidence supporting their ability to reduce DOMS and improve the recovery of physiological capacity after strenuous exercise, but when it comes to optimizing recovery, these tools and approaches give very, very minor benefits when compared to more important recovery strategies. By far the best recovery strategies are sleep and proper nutrition. I think sometimes athletes get far too caught up in devices and fancy approaches for optimizing their recovery, to the point where recovering can become a chore or stress in and of itself. As an extreme example, imagine a typical age group athlete that trains regularly for triathlon and puts in 10-15 hours of training each week on top of family commitments and job responsibilities. Now imagine this athlete falls prey to believing they need to be doing everything possible to optimize their recovery between training sessions. With all of the tools, gadgets, and approaches out there, this athlete could be spending hours each week driving to cryotherapy sessions, mulling over their entire body with massage guns and foam rollers, obsessing over getting their recovery boot sessions in, stressing about getting to the sauna, and the list of recovery ideas and opportunities goes on and on. However, if this same athlete focused on training well, sleeping 7-9 hours each night, and eating a nutritious diet sufficient in calories, macronutrients, and micronutrients, they will have won 99% of the recovery battle. Sleep and proper nutrition help aid the body in optimizing its recovery processes, and remember, the cascade of events after hard training sessions (like inflammation) is a good thing and is exactly what the body needs in order to promote positive long-term adaptation. So, anything you can do as an athlete to help support the body in these processes is what will ultimately help optimize recovery, and sleep and proper nutrition do just that. But, and this is a big “but”, sleep and proper nutrition don’t make for “sexy” selling points in a company’s marketing plan as they can’t make any money off of telling people to sleep more and eat a well-rounded and adequate diet. Keep in mind that companies selling “recovery” products, whether supplements, tools, or devices, are TRYING to make as much money as possible even if the product itself is not supported by science or evidence. So, in sum, while there could possibly be benefits to some recovery tools and modalities like cryotherapy, keep the focus on good sleep and proper nutrition first when looking to optimize recovery. Then, my best piece of advice after these two are optimized, is to pick one or two other strategies that you like and use them regularly. In an ideal world, the approaches you choose would have evidence to back up their effectiveness, but research on various recovery modalities is still evolving and we don’t necessarily know which ones work or don’t work with absolute certainty. And because the placebo effect is so powerful and likely to be where most of the benefit of various recovery modalities comes from anyways, if you like it, believe in it, and use it regularly, it is probably helping you to some extent. Does cryotherapy have evidence to support its hype? Absolutely not. It is not a miracle recovery modality like some companies or athletes might make it out to be, but if you personally love it, have the money to spend on it, and feel a benefit from it, then have it. Just make sure you have sorted out your sleep and nutrition first! References: Alexander J, Allan DR, Rhodes DD. Cryotherapy in sport: a warm reception for the translation of evidence into applied practice. Research in Sports Medicine. 2021 Mar 12:1-4. Hohenauer E, Taeymans J, Baeyens JP, Clarys P, Clijsen R. The effect of post-exercise cryotherapy on recovery characteristics: a systematic review and meta-analysis. PloS one. 2015 Sep 28;10(9):e0139028. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Cryotherapy for Athletes: Does the Evidence Support the Hype? content media
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Ryan Eckert, MS, CSCS
Jun 30, 2021
In The VO2 Max Forum
What is Heart Rate Variability? Heart rate variability, or HRV for short, has become popularized by mainstream media and technologies in recent years. The most common example of a piece of technology that many athletes utilize that uses HRV is the Whoop strap; however, there are many other devices that will measure HRV as well. The Whoop strap in particular has gained more and more popularity of late, and I can’t help but wonder how many athletes and coaches really understand HRV and what the research behind it suggests? It’s not as straightforward as you might think. Before we dive into the research behind HRV, however, we first need to discuss some basic heart anatomy and physiology. The heart has four main chambers (see Figure 1): Right atrium – receives deoxygenated blood from the body’s periphery Right ventricle – pumps deoxygenated blood to the lungs where it picks up oxygen Left atrium – receives oxygenated blood from the lungs Left ventricle – pumps oxygenated blood to the body’s periphery Figure 1. Basic anatomy of the heart Retrieved from: https://en.wikipedia.org/wiki/Atrium_(heart) Each chamber of the heart doesn’t contract in unison. The different chambers contract at slightly different time points during the contraction of the heart. When these chambers of the heart contract, an electrical signal is produced. An electrocardiogram (ECG or EKG for short) picks up on these electric signals and can depict the depolarization (electrical signal that leads to contraction) and repolarization (electrical signal that leads to relaxation) of each of the heart’s chambers. Figure 2 below depicts a typical and normal ECG. Figure 2. Typical electrocardiogram Retrieved from: https://en.wikipedia.org/wiki/Electrocardiography Many might remember this standard ECG diagram from some of their high school or college anatomy and physiology courses. Essentially, the P-wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T-Wave represents ventricular repolarization. Atrial repolarization is hidden behind the QRS complex as they both occur at the same time. Keep in mind that the depolarization and repolarization of the ventricles and atria are not synonymous with muscular contraction and relaxation. The electrical activity picked up on an ECG is the electrical activity of the heart, not the mechanical activity of the heart. However, heart contraction shortly follows depolarization and relaxation shortly follows repolarization. Now, why does this all matter you might be wondering? That is because HRV is essentially measuring the time between each R-R interval on an ECG, or in other words, the time interval between each ventricular depolarization of each heartbeat. In a healthy individual, there is a varying duration of time between ventricular depolarizations (or the QRS complex) that is influenced by the breathing cycle. In other words, there is variation in the duration of time between each beat of the heart throughout your normal breathing cycle, also known as respiration cycle. Why is there variation throughout a respiration cycle? It has to do with the influence that respiration has on vagal tone, or vagus nerve stimulation (1). The vagus nerve controls sympathetic and parasympathetic activity of the body. A decrease in the stimulation of the vagus nerve leads to greater sympathetic activity and an increase in heart rate. An increase in the stimulation of the vagus nerve leads to greater parasympathetic activity and a lower heart rate. Think of sympathetic activity as stimulating a greater stress response and parasympathetic activity as stimulating a greater relaxation response. For example, someone exercising vigorously is in a very sympathetic state and someone doing meditation might be in a very parasympathetic state. Inhalation causes an increase in pressure within the lungs, which is known to trigger inhibition of the vagus nerve (known as the lung inflation reflex) and an increase in heart rate. Exhalation, therefore, leads to a reduction in pressure within the lungs, a subsequent increase in vagus nerve stimulation, and a decrease in heart rate. This is a very long-winded way of stating that when you inhale, heart rate increases slightly, and when you exhale, heart rate decreases slightly. This is what is known as HRV, or the variability in time between each heart beat during normal respiration at rest. It is important to understand the underlying anatomy and physiology of heart rate during the respiratory cycle at rest as, like I have mentioned, this is how we measure HRV. Typically, HRV is assessed by a device measuring the electrical activity of the heart or via detecting pulse rate somewhere along the surface of the skin. The former is less commonplace in the real world as it requires being hooked up to an ECG. The latter, however, is how must commercial devices measure HRV. A device is worn at the wrist and detects the pulse of the arteries running along the wrist. It is always measured when at rest and not during activity or exercise. What is HRV Typically Used for in Athletes? There has been a plethora of research documenting that greater HRV at rest in adults is associated with better health outcomes and lower risk of chronic disease in general (2). This is because a greater HRV is usually indicative of a greater parasympathetic (i.e., relaxation) state at rest, which is a good thing and is associated with things like lesser total body inflammation and healthier diurnal cortisol patterns. In athletes, however, HRV is used less for determining health outcomes and more in determining fatigue or stress levels. It is postulated that a greater HRV is indicative of a more rested state and a lower HRV is indicative of a state of greater fatigue. At a certain threshold, if HRV gets low enough for long enough, it is thought to be indicative of an overreached or overtrained state. Someone who does no training, or casually exercises for health, and leads a very relaxed lifestyle may carry minimal to no residual fatigue and physiological stress. A dedicated endurance athlete who trains regularly may be carrying around a healthy amount of physiological fatigue and stress on a daily basis. An athlete who pushes their body too hard too often and does not provide adequate recovery between training sessions and training weeks may begin to carry too much fatigue, putting them in a state of functional overreaching with noticeable performance decrements. If the athlete then continues to push themselves, their fatigue and stress levels continue to build to the point where they are in a state of non-functional overreaching, performance starts to decline significantly, and health may be impacted. If the athlete continues to maintain their usual training habits, they may eventually exceed their body’s capacity to handle stress and the body then breaks down. This is known as overtraining syndrome, and it carries with it significantly reduced performance and serious health consequences. Full-blown overtraining syndrome can take months or years to recover from! Figure 3 depicts the continuum of fatigue to better put these terms into context. Figure 3. Continuum of fatigue Because of the need to manage fatigue and training stress, it is postulated that by measuring HRV on a daily basis, an athlete can use HRV to inform training decisions, namely whether or not to do intense training on a given day based on HRV. For example, if an athlete has a very hard training session scheduled, but their HRV is really, really low, it could be suggested that the athlete do an easier session to promote recovery and attempt that hard training session the next day if their HRV recovers a bit. Many commercial products and devices on the market that athletes use take HRV into consideration along with sleep data gathered from the device to provide a “recovery score” of some sorts through which the athlete can use their best judgement to make training decisions. However, coaches and practitioners working with athletes might just have athletes they work with gather HRV and upload it into a training software so that the coach can make training-related decisions based on their HRV trends. Keep in mind, this is the theory and general idea surrounding HRV. As we will see next, the research is a bit murkier and less clear cut than what is described above. Let’s dive into this research next. What Does the Research Say About HRV in Athletes? Fortunately, there has been an increasing number of studies utilizing HRV among untrained, well-trained, and elite athletes. There have been some studies that have compared the utilization of HRV to guide training and compared this to a “normal” training approach, with some of these studies showing promising results. For example, a 2016 study by Vesterinen and colleagues (4) divided 40 recreational runners into an HRV-guided experimental group and a traditional pre-defined training group. After a 4-week baseline training period, the traditional group trained according to the pre-defined schedule of workouts for 8 weeks, which included 2-3 moderate-to-high-intensity workouts each week. The HRV-guided group also followed an 8-week training plan; however, they utilized a 7-day rolling average of HRV values to determine what session to do on a given day. If HRV values were high and indicative of good recovery, they would go ahead with whatever workout was planned for that day, including if it was a high-intensity workout. If their HRV was lower and they had a high-intensity workout planned, they would do an easy session instead based on the feedback from the HRV measurement. Both VO2 max and 3,000 meter running performance were measured before and after the 12-week study period. The number of moderate and high-intensity training sessions completed was lower in the HRV-guided group (13.2 +/- 6.2 sessions in total) compared to the traditional group (17.7 +/- 2.5 sessions in total), but the HRV-guided group saw statistically significant improvements in 3,000 meter running performance while the traditional group did not. VO2 max significantly improved in both groups. This study concluded that there is potential to use HRV to guide and inform training decisions, namely when to do higher-intensity sessions or when to scratch it for an easier session. Other studies with similar approaches have found similar results (6,7). These studies, however, were all done on untrained or moderately-trained endurance athletes. There has been research to document that the HRV responses to training vary considerably between recreationally-trained athletes and elite athletes. In elite athletes, HRV has been documented to have no apparent pattern in relation to training load, with some athletes seeing increases in HRV, others seeing decreases in HRV, all despite none of these athletes being in a non-functional overreaching state or overtrained state (3). Even among elite athletes that did achieve a non-functional overreaching state or overtrained state, HRV data remained equivocal, with HRV being increased, decreased, or not changing at all (3). Finally, it has also been shown that in some recreationally-trained and elite athletes, HRV may actually decrease during training, rebound to be higher than normal pre-training levels during a taper or pre-race recovery period (possibly signaling positive adaptation to training), and then decrease back to normal levels a few days out from a major competition (3). Conclusions This may all sound a bit confusing, and it is, as the research is still relatively new and not as clear-cut as we may like it to be yet. There is not necessarily enough sound evidence to definitively say that we should all be using HRV to guide our training decisions, but this is not to say that it cannot still be a useful tool that can give us information that we take into consideration. It is just how you use this information that matters. So, if you already use a device or are wanting to get a device that takes HRV measurements for you and compiles that data into a graph by itself or combines it with other data to give you a “recovery” score, here is how I would suggest using that device and data: For the first 2-4 weeks, just get a baseline of your norms, gather the data, don’t use it to inform training decisions, and just watch it. Get used to seeing how HRV or recovery scores change after easy days, hard day, easy weeks, hard weeks, races, etc. Get a feel for how you as an individual respond, as research is pretty clear that everyone has their own unique HRV responses to training (3). After you have watched and waited for a few weeks, then look at trends in your data over time and start noticing patterns and relationships. If you notice that certain HRV values or recovery scores usually precede a bad string of workouts in which you feel flat or tired, well then this is a relationship to consider and utilize to make a training decision in the future. If you notice your HRV or recovery score drops to a certain level for a period of time before you get sick or start to notice injuries or niggles, this is a worthwhile relationship to take note of and utilize to inform training in the future. Although there are multiple studies that may indicate HRV-guided training programs can elicit superior performance results to a non-HRV-guided approach, there are still a small number of these studies and some have been done on relatively untrained individuals (which is not the vast majority of endurance athletes). Therefore, I would refrain from skipping or modifying hard workouts on the basis of one single bad HRV value or recovery score value as you very well might have a great workout that day despite what the data tells you. Try not to get too caught up in day-to-day changes in HRV or recovery scores, as these daily changes can sometimes be meaningless. It is more the longer-term trends you would want to take note of. Again, if you start to notice trends over time, low HRV values below a certain point that usually always precede a bad workout, then this would be what you might want to consider and then maybe start to scratch hard workouts on the days in which you see a really low HRV value. The research is still new and it does not offer us definitive answers yet. Much more research is needed before we go as far as prescribing training based on HRV, and to be honest, I do not know if we will ever, nor should we ever, prescribe training based entirely on a piece of data as there is so much more to how we feel than a single physiological value. However, HRV is a very promising tool for informing training, and it is definitely something worth exploring if you are interested. Just be sure to avoid getting too caught up in the daily fluctuations of the data and to take into account other pieces of data, such as how you actually feel! You never know, your HRV may say one thing, but if you feel great, then let it rip! References: Chapleau MW, Sabharwal R. Methods of assessing vagus nerve activity and reflexes. Heart Fail Rev. 2011;16(2):109-127. doi:10.1007/s10741-010-9174-6 Singh N, Moneghetti KJ, Christle JW, Hadley D, Froelicher V, Plews D. Heart rate variability: an old metric with new meaning in the era of using mhealth technologies for health and exercise training guidance. part two: prognosis and training. Arrhythmia & electrophysiology review. 2018 Dec;7(4):247. Plews DJ, Laursen PB, Stanley J, Kilding AE, Buchheit M. Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring. Sports medicine. 2013 Sep;43(9):773-81. Vesterinen V, Nummela A, Heikura I, Laine T, Hynynen E, Botella J, Häkkinen K. Individual endurance training prescription with heart rate variability. Medicine and science in sports and exercise. 2016;48. Kiviniemi AM, Hautala AJ, Kinnunen H, Nissilä J, Virtanen P, Karjalainen J, Tulppo MP. Daily exercise prescription on the basis of HR variability among men and women. Medicine and science in sports and exercise. 2010 Jul 1;42(7):1355-63. Kiviniemi AM, Hautala AJ, Kinnunen H, Tulppo MP. Endurance training guided individually by daily heart rate variability measurements. European journal of applied physiology. 2007 Dec;101(6):743-51. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Understanding Heart Rate Variability and its Use in Endurance Sport content media
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Ryan Eckert, MS, CSCS
May 26, 2021
In The VO2 Max Forum
What is “Durability”? Most endurance athletes I come across are familiar with terms such as “VO2 max”, “threshold”, and “movement economy”. These are all physiological characteristics of an athlete that can be measured in a laboratory (or estimated in the field), monitored over time to assess progress, and used to inform decisions related to training prescription and race pacing. There is a plethora of research that has accumulated in the past few decades demonstrating that higher VO2 max, greater lactate thresholds, and better movement economy are all associated with better performance as an endurance athlete, both among elites and amateurs alike (1). However, there is much more to an endurance athlete than just these three physiological characteristics. The concept of “durability” is a relatively novel one that proposes that endurance athletes experience a degradation in their VO2 max, threshold, and movement economy over time during prolonged exercise (2). For example, if you have a threshold run pace of 7:00 min/mile, your threshold run pace is likely not still 7:00 min/mile two hours into a marathon as you have accumulated fatigue and your original threshold was set when you were fresh. Have you ever noticed on a long bike ride, a long run, or during a long race like an Ironman or a half-Ironman that your heart rate changes over time? Usually, heart rate and perception of effort increases over time even if speed/pace or power output remains constant. This is because there is really no such thing as true “steady state” exercise. The cost of a given exercise output will increase over time as glycogen stores are depleted, as body temperature rises, and as fatigue sets in. This is essentially an athletes durability. How long can an athlete go before fatigue sets in and the physiological cost of maintaining their current pace or power increases? It is important to know that there are huge differences in durability between athletes. For example, two athletes might have the exact same threshold power output on the bike (250 watts), but one athlete might be able to hold 225 watts for 3 hours before reaching exhaustion whereas the other athlete might only be able to hold 225 watts for 75 minutes before they reach exhaustion. This is a huge difference between athletes that both might look equally “as fit” on paper if one only looked at their threshold power. This scenario is applicable to all endurance activities, not just cycling. Typically, as an athlete gets fitter and gains more years of training experience, their durability usually improves and they are able to hold paces and power outputs for longer periods of time before fatiguing, including paces and power outputs across all ranges of intensities. This is one physiological characteristic that separates professionals from most amateurs. Typically, professional endurance athletes can hold high percentages of their VO2 max or threshold for very long periods of time when compared to amateurs. This is related to greater durability! Most athletes over-obsess with their functional threshold power on the bike, or their threshold pace on the run, or their 100, 500, or 1,000-yard time in the swim. While these metrics are an important piece of the overall puzzle that makes up a complete athlete profile, these are not everything. Let’s say you have a current threshold run pace of 7:15 min/mile (the pace you could hold for approximately an hour, give or take). You train for 12 weeks and it improves to 6:50 min/mile. You would be happy with this, of course, as would a coach. Now let’s say you train for another 12 weeks and you don’t see any improvement in your threshold run pace, but you can hold a 7:15 min/mile pace for 30-45 minutes longer than you ever could before as demonstrated by setting a new half-marathon best of 1:35:00 whereas before you could only hold 7:15 min/mile pace for a 10K. This improvement would obviously make you very happy, as would it make any coach happy as well. The improvement you saw in being able to hold 7:15 min/mile for a half-marathon distance run as opposed to just a 10K run is likely indicative of an improvement in your durability. In other words, you could hold a 7:15 min/mile pace for longer without fatiguing and slowing down. This is improved fitness even without an improved threshold run pace! What Contributes to an Athlete’s Durability? What makes an athlete more durable? Well, usually the things that end up fatiguing us and cause us to slow down are related to our ability to regulate our temperature, our muscles’ ability to contract repeatedly for prolonged periods of time, our ability to move through space with as little energy consumption as possible, our glycogen storage capacity, among other factors. So, an improvement in any of these arenas would likely lead to an improvement in durability. For example, an increase in blood plasma volume due to regular training and exposure to training in hot conditions would give you an improved ability to regulate your core temperature and dissipate heat, thereby allowing you to hold a constant pace or power output for longer in warm and cooler conditions. Another example, an improved capacity to metabolize fat for fuel at submaximal exercise intensities would allow you to spare glycogen utilization and allow your body to exercise for longer periods of time without running out of glycogen to fuel exercise. This would ultimately mean you could exercise for longer without fatiguing and slowing down. One more example, an improvement in running economy from years and years of consistent low-intensity training would allow you to run at a given exercise intensity with less oxygen consumption and a lower utilization of calories to fuel that exercise. This has a myriad of physiological effects that ultimately allow you to run for longer with less effort, therefore accumulating less fatigue and delaying the need to slow down. How Does an Athlete Train Durability? The research surrounding the concept of durability is still relatively, somewhat vague, and many factors relate to an improvement in durability. However, training for improved durability is essentially training to resist fatigue for longer, and there are many approaches we know that help us in resisting fatigue for longer. There are essentially two types of durability that an endurance athlete might want to train: the ability to hold steady or constant paces or power outputs for prolonged periods of time (e.g., steady state races like in a non-drafting triathlon, a marathon, ultra-marathon, marathon swim, etc.) the ability to perform repeated bouts of very high-intensity exercise over and over again (e.g., stochastic races like in a bicycle criterium race or a mountain bike race) So, in order to train durability, you have to know which type of durability you want to train for. Are you a distance runner looking to run a fast marathon? Or are you a cyclist looking to win a local criterium? First and foremost, all endurance athletes will want to train their body’s ability to move efficiently (movement economy), their body’s ability to metabolize and use fat for fuel, their body’s ability to regulate its’ internal temperature, their body’s ability to store glycogen, and their body’s ability to intake and deliver oxygen to the working muscles. This is not an exhaustive list of the qualities athletes will want to train, but it captures some of the big ones. How do you train to improve these characteristics? We know that training consistently, training for long periods of time, and spending a lot of time training at easy/aerobic exercise intensities can improve many of these characteristics mentioned above. One of the biggest mistakes most endurance athletes make is not training enough at lower intensities and training too much at moderately-hard intensities. A lot of durability comes with training at low intensities and training a lot as this improves so many physiological and metabolic qualities within an athlete that makes them more durable and better able to resist fatigue. In order to train a lot, you have to manage your intensity as an athlete, and it is for this reason that a polarized training approach is so critical for any endurance athlete. I have written on the topic of a polarized training approach previously in many of my posts, but if you are unfamiliar with this evidence-based method of managing intensity distribution in training, I would highly recommend reading the published paper by Hydren and colleagues from 2015 (3) or listen to a podcast I did on this topic. Next, and as I mentioned previously, you will then have to consider what type of race or event you are targeting. If you are training for a steady-state race like an Ironman or a marathon, you will want to spend more time training at your target race paces, power outputs, or efforts as your body will become more efficient at this pace/power/effort the more you train at it. This is essentially what “competition-specific” preparation is within a periodized training plan. During this phase, an athlete shifts their focus from more general fitness development to more specific fitness development to match the demands of race day, including spending lots of time at and around target race pace, power, and effort. Example training sessions might look like the following: a 90-min run comprised of: 10-min warm-up, 20-min @ steady pace, 20-min @ goal Ironman 70.3 pace, 20-min @ faster than goal Ironman 70.3 pace, 10-min cool-down a 4-hour long ride comprised of: 1-hour warm-up, 2 hours Ironman power (50-min @ Ironman power, 10-min harder than Ironman power, x2), 1-hour easy cool-down If you are training for a more stochastic event in nature, like a mountain bike race or a criterium bike race, you will want to train your ability to do repeated high-intensity efforts or power outputs over and over again even under fatigue. This usually requires, again, specific training during the competition-specific phase of your plan. Example training sessions might look like the following: a 120-min bike ride comprised of: 15-min warm-up, 30 rounds of 1-min @ 400 watts with 2-min recovery spin (90-min), 15-min cool-down a 3-hour long ride with 10 x 30-sec sprints w/ 150-sec of recovery at the end of the ride Managing training intensity distribution and training consistently for months and years is likely the biggest training-related factor that contributes to improved durability. However, other training-related factors can also yield improvements that make you a more durable athlete. For example, durability might also be improved by training your ability to thermoregulate and dissipate heat as well as your ability to use fat as fuel, both of which I have written about previously here (heat on training/racing) and here (fasted training). It is plausible that an appropriately designed strength training program can improve durability due to strength improvements and efficiency gains. I have also written on the topic of strength training for endurance athletes here and here. Again, the research on the topic of durability is still relatively new and a little vague, but essentially, anything that improves your body’s ability to tolerate exercise intensities for longer periods of time or to do repeated high-intensity bouts of exercise for longer could be thought of as being related to an improvement in durability. How Does an Athlete Monitor or Track Changes in Durability Over Time? Monitoring improvements in durability is a little tricky as there is not necessarily a single measure or metric that we can test for to tell us how durable you are as an athlete. More broadly speaking, if you can hold power outputs on the bike, paces on the run, or paces in the water for longer periods of time than you used to be able to with the same heart rate or a lower heart rate, then that would be indicative of an improvement in your durability. On a more granular level, however, it becomes more difficult. Dr. Stephen Seiler, one of the leading researchers on the topic of durability, typically quantifies durability with a “decoupling” metric within a training session (3). He tracks internal load (% heart rate reserve) and external load (% of 6-min maximum power on the bike or pace on the run) over the course of a training session or race. As heart rate rises over time, there can be a noticeable decoupling of the heart rate and power output or heart rate and pace. The more these “decouple” from each other, the less durable that athlete was in that session or race essentially. To get a better sense of how this looks, I would encourage you to check out the paper published by Maunder and Seiler from 2021 (3) as there are graphical depictions of this decoupling metric using some athlete case profiles. For those of you that use TrainingPeaks, they generate a metric they call “aerobic decoupling” for bike and run sessions that is similar to the one Dr. Stephen Seiler uses. The “aerobic decoupling” metric essentially shows you how much your heart rate drifted in comparison to your pace or power output over the course of the training session or race by taking your average pace/power and heart rate from the first half of your session and comparing it to your average pace/power and heart rate from the second half of your session. The higher the number, or the higher the percentage as it is expressed in TrainingPeaks, the greater the decoupling between your heart rate and power/pace. The more durable an athlete is, the less their heart rate will decouple from their pace or power output in sessions or in races. With this aerobic decoupling metric in TrainingPeaks, one might look to this metric over time to see if heart rate decouples less and less from power or pace. The key here is to make sure you compare similar training sessions (both in intensity and duration) that were performed on similar terrain and in similar environmental conditions. For example, if you do 90-min aerobic long runs on a similar loop pretty often, these could be great sessions to look at the aerobic decoupling metric for signs of improved durability. The same could be done for a standard long bike ride you do frequently. Just remember, environmental conditions and terrain play a large role in influencing your heart rate response to typical paces or power outputs. So, when conditions change and get more challenging (i.e., it gets warmer, you go to higher altitude, etc.), know that these sessions may not be best to compare with sessions done in easier conditions (i.e., cooler temperatures, lower altitudes). However, in general, the aerobic decoupling metric can be a great metric to look at over time to see changes in your durability. It is also a great metric to look at for races as well because a very high decoupling metric may indicate a weakness in your durability. If you are going to look at this metric often in training sessions and races, just be sure you use an accurate heart rate monitor (chest strap ideally) and you gather pace and power data accurately (GPS watch and valid and reliable power meter). To provide a practical example, I have included two figures below showing half-marathon run splits for a single athlete from Ironman 70.3 Arizona in 2017 and then Ironman 70.3 Arizona 2019. The run split in 2019 was at a faster pace (7:41 min/mile compared to 8:17 min/mile), done at a similar average heart rate (170 bpm compared to 173 bpm), and completed with a lower aerobic decoupling metric (Pa:HR or 6.52% compared to Pa:HR of 7.87%). You will also notice that the athlete walked many more times (primarily through the aid stations) in 2017 and far fewer times in 2019. The weather conditions for these races were comparable (it was a little warmer in 2017) and the run courses were only slightly different (run course changed in 2019 but was very similar). The athlete also got fitter in terms of their threshold pace on the run and accumulated two years of consistent training. Taken together and comparing these two race files, the athlete likely improved their durability, alongside other fitness improvements, between 2017 and 2019 due to a faster half-marathon at a similar heart rate and a lower aerobic decoupling metric. However, the aerobic decoupling metric from 2019 was still a little high at 6.52% (TrainingPeaks usually suggests <5% indicates decent aerobic durability and aerobic fitness; https://www.trainingpeaks.com/blog/aerobic-endurance-and-decoupling/, indicating that this athlete could spend more time improving their durability and aerobic endurance. Figure 1. 2017 Ironman 70.3 Arizona Run Split Figure 2. 2019 Ironman 70.3 Arizona Run Split Conclusions As endurance athletes, there is no doubt that physiological characteristics such as VO2 max, lactate threshold, and movement economy are important factors determining success. However, durability is an often overlooked and under-appreciated physiological quality that has recently been getting more attention in the research literature as an important determinant of endurance success. Herein, I highlighted what durability is, why it matters, how to train it, and how to monitor it over time. Next time you are out on a coffee shop ride with your buddies, push the usual conversation of functional threshold power aside and have a chat about durability! After all, functional threshold power doesn’t matter much if you don’t have the durability to actually sustain that power output without fatiguing! References: 1. Joyner MJ, Coyle EF. Endurance exercise performance: the physiology of champions. The Journal of physiology. 2008 Jan 1;586(1):35-44. 2. Maunder E, Seiler S, Mildenhall MJ, Kilding AE, Plews DJ. The Importance of ‘Durability’in the Physiological Profiling of Endurance Athletes. Sports Medicine. 2021 Apr 22:1-0. 3. Hydren JR, Cohen BS. Current scientific evidence for a polarized cardiovascular endurance training model. The Journal of Strength & Conditioning Research. 2015 Dec 1;29(12):3523-30. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Understanding the Importance of "Durability" for Endurance Athletes content media
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Ryan Eckert, MS, CSCS
Apr 30, 2021
In The VO2 Max Forum
Ironman and Ironman 70.3 Racing Most triathletes are well aware that racing, and even training for, Ironman and Ironman 70.3 events does a number on the body and the mind. Training for a long-distance triathlon event that takes 4-7 hours (Ironman 70.3) or 8-17 hours (Ironman) is mentally and physically demanding. It takes careful planning and consideration of training intensity and training volume to manage the amount of stress and strain that an athlete experiences, otherwise the athlete can find themselves in a state of burnout or injury. The mental toll that heavy training loads take on athletes preparing for Ironman and Ironman 70.3 racing should also be considered. Some age group athletes will train 10-20 hours per week to prepare for these events, with professionals training upwards of 30-40 hours per week. The sheer volume of training will inevitably start to have a psychological impact. It is for these reasons above that a periodized approach to training is important in helping athletes prepare appropriately, maximize performance, and minimize any possible risk of poor outcomes. In general, moderate and relatively short duration exercise (e.g., a 30-minute brisk walk) is good for us immediately afterwards and in the long-term. However, when exercise starts to become more extreme (e.g., a 4-hour bike ride with some intervals mixed into the middle of it), the immediate impacts that the body experiences after the session begin to change. In some studies, there have been immediate deleterious impacts noted in the body’s inflammatory balance and immune system balance (1, 2). In other words, the more extreme the exercise, the more of a toll the body takes and the more it shows up immediately after the session. It does make some intuitive sense, however, as in order to see long-term positive adaptations, the body needs to be stressed in a way that it is not accustomed to followed by a period of recovery. Gentle and moderate exercise is not enough of a stress to improve athletic performance and it is likely not significant enough to throw our body’s internal environment out of homeostatic balance either. However, the type of training that most triathletes engage in certainly can throw things out of balance for a bit. A very tangible example of this is delayed onset muscle soreness that an athlete might experience after a hard run session or a heavy gym session. There are multiple reasons why delayed onset muscle soreness occurs, including potential micro-tearing of the muscle fibers to a pro-inflammatory response from damage incurred during the training session itself. However, the short-term damage and degradation ultimately, with the proper recovery, leads to the body bouncing back stronger and fitter than it was before. This is a concept known as supercompensation, and is essentially training in a nutshell: break the body down a bit, let it recover properly, break it down a bit more, let it recover again, and then show up to race fitter (i.e., capable of a higher exercise output) than you were previously. However, what athletes and coaches sometimes might forget is just how stressful the actual event/race itself is on the body. While training is stressful too, usually athletes perform at a capacity and output that they don’t usually achieve in training. We rarely push our bodies to the absolute limit in any single training session, but race day is where athletes usually get close to that limit. So, what happens when athletes race a long-distance triathlon like an Ironman or an Ironman 70.3 event? Acute Effects of Ironman & Ironman 70.3 Racing An interesting 2020 paper published by Mrakic-Sposta and colleagues (1) describes the acute effects of Ironman and Ironman 70.3 racing on oxidative and inflammatory stress experienced by athletes. Essentially, the researchers in this study measured markers of oxidative stress and markers of inflammation before and immediately after 13 Ironman 70.3 athletes (age ~ 43 years) and 19 Ironman athletes (age ~42 years) competed in a single-day triathlon event. The findings were not necessarily too surprising as markers of oxidative stress and markers of inflammation increased after participants completed their race. Oxidative stress, as measured by reactive oxygen species (ROS) in the body, increases as exercise intensity and duration is greater and greater. High levels of ROS can cause damage to other cells and can signal an immune response that creates a more pro-inflammatory environment. Hence, it is not all too surprising that there were signs of greater oxidative stress and greater inflammation after athletes finished either an Ironman or Ironman 70.3 event as they performed a large volume of exercise at a relatively high intensity (i.e., it was a race). However, a few interesting additional findings were that oxidative stress was greater in older athletes, greater in those that trained more days/week in the final 2 weeks leading into race day, and inflammation as measured with the biomarker interleukin-6 (IL-6) was inversely correlated with the number of hours/week that an athlete trained in the last 2 weeks leading up to race day (i.e., IL-6 was lower in those that trained more in the last 2 weeks leading up to race day). However, all of these correlations were relatively small, albeit statistically significant. Conclusions So, what can we take away from this 2020 study discussed above? Well, it confirms what we already sort of suspected, that a single-day ultra-endurance event like an Ironman and Ironman 70.3 event poses a significant stress on the body’s internal environment. This study in particular looked at markers of immune function, oxidative stress, and inflammation. To no surprise, oxidative stress and inflammation was elevated in athletes immediately post-race. However, there were likely further damage or homeostatic imbalances incurred by the athletes that was not necessarily measured or captured in this study, such as muscular damage, dehydration, etc. One takeaway from this study is as follows: The necessity for full and proper recovery after a very strenuous race such as an Ironman or Ironman 70.3 event should not be taken lightly. The good news is that all of the markers or signs of “damage” in athletes after a race like an Ironman or Ironman 70.3 will likely disappear within a few days or weeks and the body will return to its normal homeostatic balance with the proper amount of recovery. There is little or no research that follows triathletes long-term throughout training and racing to see what happens internally over weeks, months, and years; but in general, with the research we have, we know that there does not seem to be any evidence to indicate that a single-day event nor chronic endurance training poses any significant health risk (2). However, recovery should be a priority after a strenuous race, and the amount of time needed to recover should be respected as over-exerting, whether through racing too often or training too hard too often, can eventually lead to the body breaking down and being in a state of burnout or injury. So, while training and racing for long-distance triathletes is ultimately a positive stress, it is indeed still a stress, and even too much of a good stress can eventually become a negative one. So, to stay healthy and to minimize the risk of overuse injury, all athletes should prioritize recovery and respect the level of stress that the body experiences in particular from long-distance races like Ironman and Ironman 70.3 events. In general, it is usually better to be a little conservative and to recover more than you think you need to after a race than it is to be too aggressive in returning to intense training or racing. References: 1. Mrakic-Sposta S, Gussoni M, Vezzoli A, Dellanoce C, Comassi M, Giardini G, Bruno RM, Montorsi M, Corciu A, Greco F, Pratali L. Acute effects of triathlon race on oxidative stress biomarkers. Oxidative medicine and cellular longevity. 2020 Jan 17. 2. Vleck V, Millet GP, Alves FB. The impact of triathlon training and racing on athletes’ general health. Sports Medicine. 2014 Dec;44(12):1659-92. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Ironman & Ironman 70.3 Racing: How Hard Is It On the Body? content media
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Ryan Eckert, MS, CSCS
Mar 29, 2021
In The VO2 Max Forum
Training Volume and Triathlon Performance Endurance athletes tend to train a lot, particularly in triathlon. Obviously, the term “a lot” is very relative as five hours of training a week might feel like a lot for a novice or untrained endurance athlete, whereas more advanced and well-trained athletes might feel like 20 hours a week is a lot. However, triathlon is a sport that typically breeds high training volumes due to the need to fit in swim, bike, and run training each week. Long-distance triathlon training (i.e., Ironman and Ironman 70.3 racing) typically demands the greatest training volume due to the length of the competitions. It is not uncommon to see some professional long-distance triathlon specialists training upwards of 30-40 hours per week during heavy training. For amateurs, it is not uncommon to see 20-hour training weeks during peak training for an event. There seems to be this pervasive notion amongst triathletes that more training is always better and will yield better performance and higher fitness levels. However, is this always the case? Is greater training volume always better? Let’s dive into some recent research to help provide some answers to these questions. Self-Reported Training Volume and Ironman Performance A recent (published in 2021) study by Sinisgalli and colleagues enrolled 99 age group triathletes (80 men, 19 women) that were participating in the 2019 Ironman Brazil. The researchers enrolled these athletes, had them complete an online questionnaire ~40 days out from race day, and then recorded their overall race time as well as individual swim, bike, and run split times from their performance. Within the questionnaire, athletes were asked questions related to weekly training volume, previous Ironman racing experience, nightly sleep duration, and about signs and symptoms related to overtraining (unintentional weight loss, perceived decreased performance, loss of energy/feelings of fatigue). Researchers were looking at relationships between these self-reported variables and performance in the 2019 Ironman Brazil race. The following are perhaps the most interesting findings from this study: 1. Total race time as well as individual swim, bike, and run times were not significantly different between those that trained up to 14 hours/week, between 15 and 20 hours/week, and more than 20 hours/week. In fact, although it was statistically significant, those training the most actually had slightly slower overall race times. 2. Triathletes that reported overtraining-related symptoms (unintentional weight loss, loss of energy, feeling of decreased performance) did significantly worse (slower race times) than those that did not report these symptoms. 3. Triathletes that has previous Ironman-distance racing experience did significantly better (lower race times) than those that did not. So, what do these findings teach us? First off, greater training volume isn’t always better. This study certainly has its limitations, primarily it’s self-report and correlative nature. Due to the study design, researchers could not establish a cause and effect relationship between training volume and performance as researchers only had self-report training volume from one point in time to relate to a single race performance. However, the findings here offer up a discussion that is important for all endurance athletes to have and to understand. First, greater training volume might lead to better performance IF the athlete can adequately recover from that training and if the increased training volume is approached sensibly. In other words, if an athlete sacrifices sleep to get in more training, this will likely lead to worse performance. If the athlete also increases training volume too rapidly and does so by doing more intensity as well, it may also lead to worse performance. Building into greater training volume should be a gradual and slow process, starting with the addition of very easy and low intensity training. Training volume increases should only go so far as the athlete can tolerate and recover from. Otherwise, this greater training volume may not lead to greater performance and may ultimately impair performance and lead to overtraining. Second, speaking of overtraining, those athletes in this study that reported overtraining-related symptoms also fared worse in their performance than those that did not. Overtraining syndrome is a complex and multi-system issue that usually deals with detrimental changes to the nervous system, cardiovascular system, musculoskeletal system, and immune system. We have no idea if these athletes had a diagnosis of overtraining syndrome in this study as this was not asked, but some of the most prominent symptoms related to overtraining, also some of the biggest warming signs, are unintentional weight loss, feelings of lingering fatigue and an overall loss of energy, and decreased performance. Those that reported these symptoms about 40 days out from Ironman Brazil ended up performing worse than those that did not. Overtraining and related symptoms are something that endurance athletes should be very aware of and should monitor regularly. If an athlete notices any of these warning signs, then rest and recovery should ensue immediately. Overtraining syndrome usually develops over months and months of ignoring these warning signs and thinking that they are part of the “normal” training process. Many athletes, particularly those that train for long-distance triathlon, think that feeling exhausted and beat up all of the time is part of the process. Some fatigue and soreness here and there are completely normal, but constant fatigue, constant soreness, reduced performance capacity, and abnormal heart rate responses to training and at rest are not part of the normal training process and should not be ignored if they are present. Overtraining syndrome is something you will want to avoid with a passion as it can take months or years to recover from. Some professional athletic careers have been ruined and terminated prematurely due to overtraining, so don’t tread lightly with this topic. Finally, athletes in this study that had previous Ironman experience did better. This could be due to many factors like greater number of years training. However, it is interesting to note that experience usually helps athletes improve as they learn how to better fuel during training and racing, how to train smarter, and also from the accumulation of years and years of training stress. Endurance sports favor those that train smart and consistently for years and years, not necessarily those that train really hard for short periods of time. Furthermore, it will usually be detrimental to train really hard too often as this can lead to overtraining syndrome and ultimately reduced performance (see some of my previous posts on polarized training intensity distribution). Conclusions Training volume and training intensity, although intensity was not discussed as much herein, are both very important to monitor with triathletes and endurance athletes more broadly. Coaches and athletes alike can sometimes get caught up in carelessly doing more and more in the hopes that they will get fitter and perform better. Some of this is driven by misconception, some of it driven by the need to look “epic” on social media. However, the best training approach is one that is smart, one that takes into account adequate recovery from training, and one that is sensible in terms of training volume and intensity. Doing more than one can handle for long periods of time will likely not yield better performance and can have very negative consequences in the long run. References: 1. Sinisgalli R, de Lira CA, Vancini RL, Puccinelli PJ, Hill L, Knechtle B, Nikolaidis PT, Andrade MS. Impact of training volume and experience on amateur Ironman triathlon performance. Physiology & Behavior. 2021 Apr 1;232:113344. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Training Volume and Performance at Ironman-Distance Triathlon: Is More Always Better? content media
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Ryan Eckert, MS, CSCS
Feb 01, 2021
In The VO2 Max Forum
Sleep and Athletic Performance We all intuitively know that sleep is important for us as athletes, but just how important is it? There are decades and decades of sleep-related research within the general, non-athletic population documenting the deleterious effects of sleep deprivation on overall psychological and physiological well-being. Sleep deprivation, or insufficient sleep, has been shown to be related to impaired cognitive function, obesity, diabetes, greater cravings for unhealthy foods, impaired glucose sensitivity, impaired protein synthesis, and altered growth hormone and cortisol secretion levels (1). Sleep deprivation also leads to a greater increase in inflammation in the body and ultimately impaired immune function (1). This could all conceivably have a negative effect on athletic performance and recovery. In athletes specifically, there has been quite a bit less research, but there is still a moderate body of evidence to show that sleep deprivation of as little as a few hours over a few days can lead to reduced performance across a range of different sports, including endurance performance (1). Not only does sleep deprivation lead to poorer physical and cognitive performance, it impairs recovery as well, although there is less research specifically examining sleep deprivation and metrics of recovery. Remember, sleep deprivation can impair muscle protein synthesis and increase the inflammatory state of the body, both of which would affect recovery. On the opposite end of the spectrum, sleep extension studies in which sleep quantity has been bolstered by a few hours has been shown to improve/restore performance across a range of sports and types of performances. How Much Sleep is Enough? So, we know that sleep is important when it comes to performance and recovery, but how much do athletes need? Non-athlete adults are recommended to achieve 7-9 hours of sleep each night; however, athletes are known to report getting less sleep than the average non-athlete adult (1). This could be due to the demands to get up early for training, technology acting as a distraction keeping athlete up at night, and demanding travel schedules for some athletes. Nonetheless, whatever the demands are, athletes likely need around 8-9 hours of sleep each night for optimal performance due to the high demands placed upon their body to perform and recover (1). There is some emerging evidence suggesting that naps taken on days where an athlete might not have slept optimally can be of benefit, but this research is still emerging (1). A practical approach is to aim for 8-9 hours of good quality, uninterrupted sleep each night. On the nights where this is not achieved, a 30-60-minute nap is recommended in the late morning or early afternoon as needed. How to Achieve Optimal Sleep? Achieving good quality and quantity sleep is not necessarily difficult, it just takes some discipline. Establishing good “sleep hygiene” habits is the best thing an athlete can do to ensure good sleep patterns. The following strategies are recommended as part of a healthy sleep hygiene routine to promote good sleep (1): Don’t go to bed until sleepy. If not sleepy, get out of bed and do something else until becoming sleepy. Regular bedtime routines/rituals help to relax and prepare the body for bed (reading, warm bath, etc.). Try to get up at the same time every morning (including weekends and holidays). Try to get a full night’s sleep every night, and avoid naps during the day if possible (if a nap is a must, limit to one hour and avoid nap after 3:00 pm). Use the bed for sleep and intimacy only, not for any other activities such as TV, computer, or phone use. Avoid caffeine if possible (if must use caffeine, avoid after lunch). Avoid alcohol if possible ( if must use alcohol, avoid right before bed). Do not smoke cigarettes or use nicotine, ever. Consider avoiding high-intensity exercise right before bed (extremely intense exercise may raise cortisol, which impairs sleep). What About Travel and Sleep? Travel is a concern that many athletes have because of its impact on sleep. Jet lag is a very real phenomenon when travelling across different time zones, especially when travelling from west to east. Research shows that travelling across time zones can have a negative effect on athletic performance, particularly within the first 72 hours after landing (1). As a rough guide, jet lag symptoms may last for about one day for each time zone when travelling eastward, and a half-day for each time zone when travelling westward (1). This period of time it takes to adjust from jet lag should be taken into account when travelling for races, in particular, as an athlete would want to allow themselves adequate time to adjust and recover from jet lag before expecting any sort of optimal performance. Jet lag when travelling northward or southward is not as well understood, but the primary impact on sleep may come from circadian rhythm disruptions due to changes in hours of sunlight (1). Athletes travelling northward or southward should try to spend as much time outside when travelling in these directions and to a new location with different daylight hours. This period of adjustment may also take a few days and should be accounted for when travelling for racing. Conclusions Sleep is arguably the most important factor in recovery. Exercise and nutrition are often thought of as the most important factors in determining performance, but sleep should be lumped in there as the third most important factor. The best training and nutrition strategies in the world will be rendered sub-par if an athlete does not sleep well or is chronically sleep deprived. Sleep should be a priority for every single athlete alongside optimizing training and nutrition strategies. Athletes should aim for 8-9 hours of high quality, uninterrupted sleep each night and establish consistent sleep hygiene patterns in order to achieve this goal. References: 1. Vitale KC, Owens R, Hopkins SR, Malhotra A. Sleep hygiene for optimizing recovery in athletes: review and recommendations. International journal of sports medicine. 2019 Aug;40(8):535. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
The Role of Sleep on Performance and Recovery in Athletes content media
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Ryan Eckert, MS, CSCS
Jan 01, 2021
In The VO2 Max Forum
What is static stretching? Static stretching is a type of stretching in which a position is held near the individual’s end range of motion or at the point of discomfort for a period of time. Static stretching, when done appropriately, regularly, and for an adequate length of time, can improve flexibility. However, static stretching has also been frequently claimed to reduce the risk of injury in athletes. Some coaches advocate for their athletes to do static stretching as part of a warm-up routine in order to reduce the likelihood of acute injuries (although the use of static stretching during a warm-up routine is a bit old school nowadays). Some coaches also claim that doing static stretching, regardless of when it is done, can prevent or reduce the likelihood of chronic overuse injuries (a type of injury that plagues endurance athletes). But can static stretching really prevent injuries in athletes? Let’s take a look at the research to see what it suggests. Can static stretching prevent injury? A comprehensive meta-analysis published by Lauersen and colleagues in 2014 (1) aimed to determine which types of exercise interventions could reduce the incidence of injury in athletes across various sports. They analyzed data from 25 studies, including 26,610 individuals and 3,464 injuries. In each of these studies, researchers enrolled healthy, non-injured athletes or individuals into an intervention program consisting of strength training, proprioception training (sort of like balance exercises), static stretching, or a multi-component intervention (a mix of strength, proprioception, and/or stretching) for a pre-determined period of time. Researchers then tracked the number of injuries that occurred over the course of the study. This meta-analysis was able to summarize all of these studies and statistically quantify which type of intervention was most effective in preventing acute and chronic injuries. Static stretching was demonstrated to NOT be effective in reducing the likelihood of injury occurrence. In fact, static stretching was the only type of intervention that was shown to be ineffective when compared to strength training, proprioception training, or doing multiple interventions. The authors from this meta-analysis concluded that static stretching was not an effective type of exercise intervention to reduce the incidence of both acute and chronic injuries in sport. What does prevent injury? This meta-analysis did, however, demonstrate that strength training, proprioception training, and multi-component interventions were all effective in reducing injuries (1). Most notably, strength training had the greatest effects, nearly cutting injury risk down to one third of the risk if there was no strength training intervention at all! Proprioception training and multi-component interventions seemed to cut injury risk in half and were slightly less effective compared to strength training alone; however, this certainly doesn’t discount the potential utility of proprioception exercises or a combination of strength training and proprioception exercises for primary injury prevention. Additionally, it seems that both acute and chronic overuse injury risk was improved, with chronic overuse injury risk faring slightly better and being cut in half compared to no intervention! This is all good news for endurance athletes looking to stay healthy and suggests that incorporating strength training or proprioception exercises into one’s routine can help prevent the risk of an acute, traumatic injury (e.g., tearing a muscle on a run) as well as reduce the risk of developing an overuse injury over time (e.g., stress fracture, IT band tendinitis, patellofemoral pain syndrome, plantar fasciitis, etc.). Conclusions In conclusion, static stretching is great for improving flexibility, but not for directly reducing the risk of injury. Strength training and proprioception training are, however, beneficial for an athlete looking to prevent injury or at least reduce their likelihood. It is important to note that completely eliminating injury in athletes is likely impossible, and anyone that has been an athlete and competed in sport for a long time knows that injuries can still happen even if preventive measures are taken and caution is taken with training. However, reducing the risk is always a win and helps improve the chances that an athlete will stay healthy and consistent with their training. Besides, strength training has other benefits for endurance athletes as it relates to performance as well! To learn about those benefits, check out a VO2 Max Forum post from January 2020 in which I discussed the science of strength training for endurance athletes by clicking here. References: 1. Lauersen, J. B., Bertelsen, D. M., & Andersen, L. B. (2014). The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. British journal of sports medicine, 48(11), 871-877. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Can Static Stretching Prevent Injury? content media
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Ryan Eckert, MS, CSCS
Nov 30, 2020
In The VO2 Max Forum
What is the placebo effect? Endurance athletes improve over time only through intervention. In other words, if an athlete does nothing (i.e., no training), then he/she will not see any positive changes in their fitness and performance. An athlete improves only when intervening through the addition of a training stimulus. Luckily, in today’s sporting world, we have a plethora of research to suggest which approaches to training are best. We also have research documenting the potential effects, or lack thereof, of various substances, tools, pieces of equipment, or psychological tactics. This research is then used by coaches and athletes alike to inform decisions on how to prepare an athlete for better fitness and performance. We are usually led to believe that if an intervention or training stimulus works, that there is a physiological or biological reason as to its success. However, what if improvements in fitness and performance can be elicited via psychological mechanisms as well? In other words, what if simply believing that something is working will elicit very real physiological and biological changes? Well, a recent area of research that has gained more and more attention is that of the placebo effect, and this phenomenon is exactly that. The placebo effect is observed when administering something to an individual that might otherwise have no physiological or biological basis for eliciting any positive change indeed leads to a positive change. However, this phenomenon is also observed when specific wording or phrasing of the effectiveness of an evidence-based and proven intervention is used to enhance or augment its anticipated effects. Here are a few examples: 1. One athlete is given a caffeine pill prior to a 1500-meter race (caffeine is a known performance-enhancing substance for endurance athletes). Another athlete is given the same pill in terms of its size, texture, look, and taste, except this one is caffeine-free. Both athletes are told, however, that they are receiving caffeine and that caffeine may help improve their performance. Both athletes see an improvement in performance. The athlete that saw an improvement in their performance despite receiving a placebo pill is experiencing the placebo effect. In essence, they believed they were receiving something that was going to help them, and this belief elicited very real biological and physiological effects, ultimately yielding an improvement in performance. 2. A coach is going over a taper strategy with an athlete a few weeks out from a big race. Rather than simple telling the athlete what to do each day in their training log, the coach decides to sit down with the athlete and explain the research documenting the beneficial effects on performance that a properly executed taper can have. The athlete listens, gets excited, executes a perfect taper period, and ultimately races well. Some of this performance may be attributable to the athlete’s belief that they executed a perfect taper while knowing that they were helping themselves to improve their performance. This is also the placebo effect at work. Now that we have defined what the placebo effect is and given a few examples, let’s cover how this phenomenon is relevant to both athletes and coaches, as the use of this knowledge is very different depending on whether you are receiving a training plan or delivering one to someone else. What should athletes be aware of as it relates to the placebo effect? Athletes should be aware that the placebo effect is a very powerful phenomenon as it relates to their performance. For example, many products out there on the market that claim to enhance performance, improve recovery time, etc., don’t have much evidence to support their claims. However, some athletes swear that a certain product improves their performance. This can be explained by the placebo effect. This is indeed a positive thing so long as that product is legal and does not come with any unwanted side effects. Recovery boots for example have no research documenting any real physiological effects on enhancing recovery, yet many athletes use them and may report that they feel like it helps them recover faster and better. These athletes may not be lying as they may indeed be experiencing recovery benefits from consistently using a product that they truly believe is helping them. The key here is their belief. Belief in something is so important as an athlete. Believing in their coach, their training plan, their race plan, and everything that they do essentially will only help them improve the results they see in terms of fitness and performance. If an athlete truly believes something is working for them, then it likely will. However, athletes should still do their research (legitimate research, not google searches and asking other athletes for their opinions) or get reputable information from a reliable source as to the science supporting various products or training approaches out there, as simply hoping the placebo effect will save them isn’t a good enough excuse to recklessly try and do everything that an athlete wants within their training and racing. Also, some products out there that have no science to back up the claims they make can be a massive waste of money when athletes could be putting that money into something that has more evidence to support it. Something that has real physiological and biological effects is still likely to “outwork” any effects that placebo effect might have from using a product that has no real physiological or biological basis for its effects. What should coaches be aware of as it relates to the placebo effect? Coaches should know that the words they speak to an athlete have a huge influence on the effectiveness of their coaching and the training plans they prepare for athletes (2). The key with anything and everything coaches do is to get the athlete to buy in and truly believe that the coach is delivering the best possible plan of action for them to achieve their goals. If the athlete believes in it, then it will likely help them. Coaches should be informed on the latest research surrounding relevant topics, and then assure athletes that the evidence-based approaches they are providing to them have documented benefits, and be specific about those benefits. The more an athlete hears of the specific benefits, the more they will buy in and believe it. A 2011 meta-analysis demonstrated across 14 interventions and 196 placebo group participants that the placebo treatment elicited small to moderate improvements across various strength and endurance-related performance outcomes (1). This is incredibly important to be aware of as this demonstrates how powerful a belief in something is when it comes to athletic performance. Of course, coaches should always deliver evidence-based approaches and tactics when possible as evidence-based approaches are always recommended over blindly doing whatever a coach wants, but getting the athlete to believe in their approach is just as important. Conclusions To conclude, know that there is far more at work when an athlete intervenes with a training stimulus or uses a product with the intent of enhancing some aspect of performance. The belief in what they are doing is just as important as actually doing it. A coach could devise the perfect and most evidence-backed plan known to mankind, but if the athlete does not believe in it, then it won’t ever be as effective as it could have otherwise been had the athlete been convinced that it was the best plan known to mankind. References: 1. Bérdi M, Köteles F, Szabó A, Bárdos G. Placebo effects in sport and exercise: a meta-analysis. European Journal of Mental Health. 2011 Dec 1;6(2):196. 2. Roelands B, Hurst P. The Placebo Effect in Sport: How Practitioners Can Inject Words to Improve Performance. International Journal of Sports Physiology and Performance. 2020 Jun 3;15(6):765-6. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
The Placebo Effect and its Role in Endurance Sport content media
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Ryan Eckert, MS, CSCS
Nov 04, 2020
In The VO2 Max Forum
What are the theoretical benefits of percussive massage devices? Handheld percussive massage devices (i.e., massage “guns”) have become popular in recent years. More and more advertisements are popping up of the popular brands that make these devices (e.g., Hypervolt, Theragun, etc.) in which claims are made of enhanced recovery among athletes at the elite and professional level. Endorsement from elite/professional athletes, however, is not enough grounds to establish whether a device works or not. Although individual testimonial is certainly useful, what is the actual theoretical premise behind which these massage guns are based on? Well, percussive devices such as massage guns seem to base their logic on the fact that they are combining massage and vibration therapy together. There is a good amount of literature to suggest that massage (either via a massage therapist or via foam rolling of some sorts) can lead to reductions in the intensity of delayed onset muscle soreness (DOMS) following intense exercise as well as lead to improvements in range of motion (3). Vibration therapy (usually applied by having an individual stand on a plate that vibrates at a low magnitude, high-intensity frequency or by having someone use a vibrating foam roller on a specific muscle) also has some evidence to support that it can lead to reductions in the intensity of DOMS as well as lead to improvements in range of motion (1,2). Therefore, it would seem that if you could combine the two and make a device that does both massage and apply some sort of vibration to the muscles that you could also receive some benefits on athletic performance. However, despite the benefits of massage and vibration therapy individually, research still needs to establish that massage guns actually do work before we claim that they do. Let’s discuss this research next. What are the actual benefits of percussive massage devices? Not surprisingly given how new these types of devices are, there is very, very little research published to date investigating the effects of percussive massage devices on athletic performance. The only study that seems to be done thus far is one very recently published by Konrad and colleagues earlier this year (4). In this study, research had 16 individual volunteers come into a laboratory on two separate occasions. On each occasion, they performed a calf (i.e., gastrocnemius) range of motion assessment and a calf maximum voluntary muscle contraction assessment (sort of a proxy test to assess maximum muscle strength in the calf muscle) after a standardized warm-up on a stationary bike. However, on one day, after the standardized warm-up, participants received a 5-min massage with the Hypervolt massage gun on their calf muscles before performing the tests; and on the other day they just sat still after the standardized warm-up for six minutes before performing the tests. When receiving the 5-min massage with the Hypervolt device, participants actually saw a significant increase in their ankle dorsiflexion range of motion (i.e., greater calf flexibility) without a decrease in calf muscle strength. When simply sitting still, participants did not see any sort of improvement in their ankle dorsiflexion range of motion. This study is interesting as it demonstrates that the massage guns could be a potentially useful tool as part of a warm-up due to the fact that it did not seem to impair muscle performance (i.e., strength) but increased range of motion around a joint. The most likely causes for this are due to the massage device increasing blood flow to the muscle, reduction in pain sensitivity, increased sensation of relaxation, reduced muscle compliance and stiffness, and also greater viscosity (i.e., less resistance to movement) of the muscle itself and the skin and fascia surrounding it. However, this study did not investigate the effects of the massage gun on DOMS following intense exercise. Therefore, it is not clear yet as to whether or not massage guns, like the Hypervolt, are useful post-exercise as a recovery tool and can lead to reductions in the intensity or length of time that one experiences DOMS after an intense exercise session. Additionally, this study did not investigate any sort of long-term range of motion/flexibility changes. So, it is also not clear if the acute improvements in range of motion can be made permanent by regular use of a massage gun. In all likelihood, these changes in range of motion are not permanent when the massage gun is used just one time. Similar to massage and foam rolling, there can be transient increases in range of motion or flexibility due to increased relaxation and a reduced sensitivity to pain (among other factors). However, would using a massage gun regularly to target “trigger points” or spots of significant muscle tension and stiffness lead to long-term improvements in mobility and flexibility? There isn’t enough research to answer this question quite yet. Furthermore, we also don't yet know quite what the optimal "dose" of massage gun usage is needed to elicit any sort of positive responses. This particular study discussed herein had participants exposed to 5-min of massage on both legs, so we know that 5-min of massage gun exposure seems to work for improving range of motion acutely. However, would less time have been just as effective? In the foam rolling literature, which I have discussed in a previous Science Post, just 1 or 2 sets of 60 seconds seem to be effective in improving range of motion acutely. Would 60 seconds of massage gun exposure be just as effective as 5 minutes? This, we do not know yet and much more research will need to be done before we have a more complete picture as to what the optimal "dose" is to see any sort of benefit. Finally, this study did have a small sample size of healthy volunteers, albeit, it was a randomized controlled trial. Due to such a small sample size and the relatively young, healthy participants included, the takeaways from this study should therefore be in the context of the limitations of study itself and the findings shouldn't be generalized to ALL types of individuals. Conclusions So far, with the one study that has been published to date on the topic of massage guns, it seems that there is some evidence to suggest that they can be useful tools during a warm-up routine before an intense exercise session. However, their benefit on recovery or long-term mobility/flexibility changes is unknown. It could be theorized that using massage guns post-exercise can lead to reductions in DOMS and potentially enhance recovery time, but the evidence isn’t there to support these claims officially quite yet. On another note, some of the more popular brands of massage guns (i.e., Hypervolt, Theragun) can be very expensive (upwards of $350-$400 for the device). In my own personal experience, I have purchased lesser known branded version of massage guns for less than $100 and they seem to do the job just as well as the more expensive branded massage guns. So, it may be worth considering trying a much cheaper brand of massage gun initially if you simply want to try out these types of devices. In my experience so far, the massage guns do feel nice after hard exercise sessions and can be quite useful in helping me warm-up before sessions as well. However, in my own opinion, $350-$400 for one of these devices is absolutely ridiculous and one should consider a cheaper alternative, particularly given the fact that there is so little evidence currently available to justify such high price points. References: 1. Cerciello S, Rossi S, Visonà E, Corona K, Oliva F. Clinical applications of vibration therapy in orthopaedic practice. Muscles, ligaments and tendons journal. 2016 Jan;6(1):147. 2. Cheatham, S. W., Stull, K. R. and Kolber, M. J. (2019) Comparison of a vibration roller and a nonvibration roller intervention on knee range of motion and pressure pain threshold: A randomized controlled trial. Journal of Sport Rehabilitation 28(1), 39–45. 3. Davis, H. L., Alabed, S. and Chico, T. J. A. (2020) Effect of sports massage on performance and recovery: a systematic review and meta-analysis. BMJ Open Sport & Exercise Medicine 6(1), e000614. 4. Konrad A, Glashüttner C, Reiner MM, Bernsteiner D, Tilp M. The Acute Effects of a Percussive Massage Treatment with a Hypervolt Device on Plantar Flexor Muscles’ Range of Motion and Performance. Journal of Sports Science and Medicine. 2020 Dec 1;19(4):690-4. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Effects of Percussive Massage Devices (i.e., Massage "Guns") on Performance content media
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Ryan Eckert, MS, CSCS
Sep 29, 2020
In The VO2 Max Forum
What are the benefits of listening to music during exercise? Most athletes today will likely listen to music during training sessions, and some will listen to music during competition if their sport allows it within the rules. Athletes that have trained or competed with and without music will likely say that listening to music helps them to some degree. Is it all placebo effect? Or, is there some physiology and psychology to it. Turns out there is! Listening to music during exercise has been shown to improve performance while simultaneously decreasing rating of perceived exertion (RPE), increasing feelings of energy, and increasing feelings of stimulation (1,2,4,5). However, some of this research suggests that the type of music one listens to is important in determining whether it provides a benefit or not. The type of music an athlete listens to should be a type and a song that they prefer! This sounds intuitive, but listening to music one does not prefer or like is much more likely to yield no benefit on performance during exercise. So, athletes should choose music they like and that they want to listen to during exercise to reap a benefit. This is fine during training sessions for most athletes, but what about competitions where performance is to be maximized? What does an athlete do if their sport does not allow music during competition? Listening to music during the warm-up can also have an effect on their subsequent performance! What are the benefits of listening to music before exercise? Listening to music during a warm-up prior to a training session, or more importantly, a competition also seems to confer a benefit, so long as that music the athlete listens to is preferred! A recent study conducted by Karow and colleagues (3) demonstrated that 2,000-meter time trial performance on a rowing ergometer was significantly improved in those that listened to their preferred music selection when compared to listening to non-preferred music or no music at all during the pre-time trial warm-up. Additionally, listening to preferred music during warm-up also led to a subsequently higher heart rate response and greater motivation when compared to non-preferred music or no music at all (3). So, it seems, similar to listening to music during exercise, selecting music that one enjoys, finds motivating and upbeat, and is preferred is key in conferring benefits on performance. Conclusions There is good news here for all athletes as there is evidence to suggest that listening to music both before and during training or competition is beneficial, so long as that music is preferred and enjoyed by the athlete listening to it. This means there is not one type of genre or song selection that works for everyone, as some may find country music motivating and others may find hip hop motivating. The specific type of music selection is up to you and your preferences. For those that are not allowed to compete with music, listening to it during their pre-competition warm-up can also be beneficial. It would be interesting to see researchers study the compared effects of listening to music during exercise and before exercise to see what provides the greatest benefit for those that are allowed to listen to it during competition, but that research has yet to be done. Until then, enjoy music before or during training and competing when and where you can as there are benefits to be had on your performance! References: 1. Ballmann, C. G., Maynard, D. J., Lafoon, Z. N., Marshall, M. R., Williams, T. D., & Rogers, R. R. (2019). Effects of listening to preferred versus non-preferred music on repeated wingate anaerobic test performance. Sports (Basel), 7(8), E185. 2. Ballmann, C. G., McCullum, M. J., Rogers, R. R., Marshall, M. M., & Williams, T. D. (2018). Effects of preferred vs. nonpreferred music on resistance exercise performance. Journal of Strength and Conditioning Research. Advance online publication. https://doi.org/10.1519/JSC.0000000000002981 3. Karow MC, Rogers RR, Pederson JA, Williams TD, Marshall MR, Ballmann CG. Effects of Preferred and Nonpreferred Warm-Up Music on Exercise Performance. Perceptual and Motor Skills. 2020 Jun 3:0031512520928244. 4. Lingham, J., & Theorell, T. (2009). Self-selected “favourite” stimulative and sedative music listening–How does familiar and preferred music listening affect the body? Nordic Journal of Music Therapy, 18(2), 150–166. 5. Nakamura, P. M., Pereira, G., Papini, C. B., Nakamura, F. Y., & Kokubun, E. (2010). Effects of preferred and nonpreferred music on continuous cycling exercise performance. Perceptual and Motor Skills, 110(1), 257–264. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
Effects of Music on Exercise Performance content media
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Ryan Eckert, MS, CSCS
Aug 31, 2020
In The VO2 Max Forum
What is sodium bicarbonate and what are the proposed benefits? Sodium bicarbonate (NaHCO3), commonly known as baking soda, is a natural salt compound composed of sodium and bicarbonate. Usually used in baked goods, its has also received attention in the research literature for sports performance since as early as the 1930s (3). This interest is even more pronounced today with more and more research literature being published in recent decades examining the effects of sodium bicarbonate ingestion on athletic performance. Why is there an interest in sodium bicarbonate for athletic performance? Well, when we exercise, particularly at higher and higher intensities, one of the byproducts is the formation of hydrogen ions. The accumulation of hydrogen ions leads to a reduced muscle pH (more acidic environment) and subsequent fatigue. We have some natural acid buffer mechanisms in our body to help maintain a normal muscle pH. During exercise, blood cells work to carry hydrogen ions and carbon dioxide (also produced as a byproduct during exercise) away from the muscle. However, in addition to this mechanism, the formation of lactate is also important in maintaining a normal muscle pH. Contrary to popular opinion, the formation of lactate during exercise is a GOOD thing as the formation of this compound helps reduce the number of hydrogen ions floating around in the muscle, thereby helping to stave off fatigue from a more acidic environment. Ingesting sodium bicarbonate also acts as a natural antacid and can help buffer hydrogen ions. The theoretical logic here is that, if an athlete ingests sodium bicarbonate, essentially they are increasing their body’s acid buffering capacity, which should help to delay fatigue at higher intensities. So, researchers began to truly study the effects of sodium bicarbonate ingestion on athletic performance in the 1970s, and that research continues today. What does the science say surrounding sodium bicarbonate? When looking at the actual science surrounding sodium bicarbonate and athletic performance, the research literature can be somewhat mixed. For each study that demonstrates a benefit of sodium bicarbonate ingestion on performance, there are just as many that show no benefit on performance. However, there have been so many studies done up to this point, that it is possible to look at systematic reviews and meta-analyses of a group of sodium bicarbonate studies. These systematic reviews and meta-analyses are the gold standard when determining the true effects of an intervention on an outcome because they usually examine a large collection of randomized controlled trials. In 2012, Peart and colleagues did just that and published a meta-analysis exploring the effects of sodium bicarbonate on athletic performance across a range of athletes, including both men and women, trained and untrained individuals, and a variety of different sports and performance measures (3). Essentially, what this meta-analysis showed was that there was a moderate effect of sodium bicarbonate ingestion on performance in general. However, this effect tended to be much higher in untrained individuals when compared to trained individuals. The thinking behind this is that trained individuals already have a well-developed acid buffering capacity through consistent training, whereas untrained individuals do not. The added buffering capacity of sodium bicarbonate for the untrained individual is therefore much greater than it is for the trained individual. Some other major takeaways from this meta-analysis included: 1. Trained individuals are likely to experience less of an effect of sodium bicarbonate on performance when compared to trained individuals; however, the slight benefit that trained individuals may experience could be relatively significant due to the smaller margins of performance between competitors at higher levels 2. Sodium bicarbonate ingestion seems to exert a moderate benefit on short (2 min or less), moderate (2-10 min), and long (10+ min) duration endurance performances 3. Sodium bicarbonate ingested at 0.2-0.4 grams/kg of body weight 60-120 minutes before exercise seems to be the recommended dosage and timing to experience benefits a. Be careful with this one when looking for supplements as many would require you to take an absurd amount of their product to fall within this recommended dosage for performance enhancement. For example, this supplement from Hammer Nutrition (https://www.hammernutrition.com/race-day-boost) would require me personally, at 75 kg body weight, nearly 30 servings/pills (half of the bottle!!) in order to achieve the lower end of this recommended range (0.2 grams/kg). This could be potentially misleading for athletes that are unaware as the recommended serving size is only 1 capsule, and this wouldn’t be nearly a high enough dose to achieve any kind of performance benefit. However, it should be noted that one of the major downsides of ingesting sodium bicarbonate (usually via a liquid or capsule) is the risk for gastrointestinal distress (gas, bloating, etc.). This can have a negative effect on performance, particularly for endurance athletes competing in long-distance endurance events. This could potentially outweigh the positives that are associated with additional acid buffering capacity. If attempting to ingest sodium bicarbonate, test it out in training to see how it affects you first before trying it out on race day. It may not be worth trying on race day if it causes unwanted gastrointestinal side effects. More recently, there have been some sodium bicarbonate creams and lotions that have been developed to try and work around this issue. AMP Human (https://amphuman.com) is one example. This is a lotion that athletes would rub on their skin, much like sunscreen or body lotion, but over the muscle groups that will be utilized most heavily during exercise. For example, a runner might rub the lotion onto their legs before exercise. The transdermal uptake of the sodium bicarbonate eliminates any risk of gastrointestinal side effects, but does this method of sodium bicarbonate uptake actually work like taking sodium bicarbonate orally does? It is a bit too early to make any sound conclusions here as there has really only been one study done examining the use of sodium bicarbonate lotion on exercise performance (1,2). Although this study showed some positive effects on performance and recovery, including an increased buffering capacity with simultaneous lower heart rate and perceived exertion during various lengths of exercise tests as well as reductions in muscle soreness in the days following intense exercise when compared to a control group, this study includes only a few subjects (N=21) and only looks at physiological workload measures (i.e., perceived exertion, heart rate, blood lactate) without examining any performance output measures. Therefore, we don’t yet know if using a lotion-based sodium bicarbonate delivery system improves performance outcomes. Additionally, one study simply isn’t enough to say whether something “works” or not. Finally, this study was sponsored by a company that makes sodium bicarbonate-based lotions, so there may be a bit of potential bias here. It is important to see more studies done specifically examining the delivery of sodium bicarbonate transdermally and its effects on performance outcomes before any kind of firm conclusion can be made. We need to better understand the dosage and timing required to see a performance benefit from a sodium bicarbonate lotion as it might be different when compared to ingesting sodium bicarbonate. Conclusions In conclusion, it seems there may be some moderate performance benefits to be gained from ingesting sodium bicarbonate in the form of a pill or liquid at 0.2-0.4 grams/kg at 60-120 minutes before exercise. These benefits may translate to both short events and long endurance events. However, trained individuals may not receive quite as great of a benefit when compared to untrained individuals. The biggest downside to ingesting sodium bicarbonate is the risk for gastrointestinal side effects, which can far outweigh the potential benefits. Therefore, lotion-based products have been recently developed in an effort to combat this issue. Despite some promising initial findings surrounding the use of a lotion to deliver sodium bicarbonate to the muscle, there simply hasn’t been enough research done yet to conclude that this method of delivering sodium bicarbonate truly works and provides a benefit to athletic performance. References: 1. Kern M, Misell LM, Ordille A, Alm M, Salewske B. Double-blind, Placebo Controlled, Randomized Crossover Pilot Study Evaluating The Impacts Of Sodium Bicarbonate in a Transdermal Delivery System on Physiological Parameters and Exercise Performance: 2402 Board# 238 June 1 1100 AM-1230 PM. Medicine & Science in Sports & Exercise. 2018 May 1;50(5S):595. 2. Misell L, Kern M, Ordille A, Alm M, Salewske B. Double-blind, placebo controlled, randomized crossover pilot study evaluating the impacts of sodium bicarbonate in a transdermal delivery system on delayed muscle onset soreness: 2403 Board# 239 June 1 1100 AM-1230 PM. Medicine & Science in Sports & Exercise. 2018 May 1;50(5S):595. 3. Peart DJ, Siegler JC, Vince RV. Practical recommendations for coaches and athletes: a meta-analysis of sodium bicarbonate use for athletic performance. The Journal of Strength & Conditioning Research. 2012 Jul 1;26(7):1975-83. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
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Ryan Eckert, MS, CSCS
Jul 31, 2020
In The VO2 Max Forum
What is a “taper”? Endurance sports is heavily reliant upon developing fitness through the accumulation of training volume and intensity over weeks, months, and even years in preparation for competition. However, in order to perform at one’s best come race day, particularly a key race on an athlete’s calendar, an effective taper is critical to ensuring a higher likelihood of success and the maximization of that athlete’s performance potential. Most endurance athletes have heard of the term “taper”, but what does it mean, what is the science behind it, and what does an effective taper look like? As with many things in the exercise science world, the answer to some of these questions is “it depends”. Designing an effective taper is both an art and a science. Luckily, we have a lot of science to justify the taper and some basic parameters surrounding how it should look in general. However, very specific, minute details are more of the art piece that the coach or athlete is in control of. As an athlete trains throughout a competitive season, they build fitness, particularly in endurance sport, by increasing their training volume, training intensity, or both. This increase in training intensity or volume is needed to stimulate improvements in fitness. However, along the way, athletes also accumulate fatigue, both physiological and psychological in nature. This fatigue masks an athletes performance, putting a hindrance on their ability to perform at their best when under the fatigue. A few weeks before a major competition, an athlete typically enters a taper phase in which the training stimulus is reduced to allow for recovery of performance while minimizing any potential loss of fitness. I like to think of the taper as “sharpening an athlete’s sword” for competition. The goal of the taper is not to train too much, but it is also certainly not to train too little. So, how much should one train? What does the taper look like? Let’s dive into the science. What is the science behind an effective taper? When it comes to the taper, there are a variety of definitions out there in the research literature, but a common one is as follows. The taper can be thought of as “a progressive linear or non-linear reduction of the training load during a variable period of time, to reduce physiological and psychological stress of daily training and optimize sports performance” (2). When designing a taper, the variables that can be manipulated include: Training volume Training intensity Training frequency Duration of the taper I will be covering the different types of tapers and what science suggests is the best way to manipulate the above variables to maximize performance. Types of Tapers There are three main types of tapers: Step taper The step taper involves an immediate, large reduction in training volume to a level that remains constant leading up to competition day. Exponential taper An exponential taper involves an immediate large drop in training volume followed by a progressively lesser and lesser drop in volume as competition day approaches. Exponential tapers can be “slow decay” or “fast decay” in nature, with slow decay tapers being a bit less extreme in the reduction in training volume compared to fast decay. Linear taper A linear taper is a steady and progressive reduction in training volume. I would consider this the most common type of taper approach that athletes and coaches take due to its simplicity. See Figure 1 below for a representation of the three different types of tapers (2): Figure 1. Schematic representation of different types of tapers How to manipulate training variables in a taper? Research tends to suggest that, with an effectively designed and well-executed taper, an athlete can expect to see a 2-3% improvement in performance on average, but this improvement can range anywhere from 0-6% depending on the athlete (2). This might not sound like much, but for well-trained athletes that are attempting to be competitive in a race, this can be the difference between winning and losing. So, how does one effectively design a taper? A meta-analysis by Bosquet and colleagues from 2007 (1) analyzed and compared progressive tapers (linear and exponential) to step tapers and found the following: A decrease in training volume tends to demonstrate the largest effects on performance when compared to a reduction in training intensity or frequency, so a reduction in training volume should be prioritized whereas training intensity and frequency should remain about the same as they were prior to the taper. A taper duration of ~8-14 days seems to yield the largest effect on performance, with tapers shorter or longer producing lesser effects on performance. Both step tapers and progressive tapers seem to be effective, but progressive tapers (linear and exponential) produced a statistically significant, small effect on performance when compared to step tapers. The following table is taken from this paper by Bosquet and colleagues (1), and I have highlighted the findings for each training variable that yielded the largest effect size on performance so you can see the characteristics that should make up an effective, evidence-based taper. Table 1. Effects of moderator variables on effect size for taper-induced changes in performance Why does a taper work? So, we have discussed the “how” and “what” of the taper, but what about the “why”? Why does a taper work to improve performance so effectively when done right? Well, there are a variety of factors, and at the most basic level, a taper helps to shed fatigue so that performance potential is maximized. The effects of a taper are physiological and psychological in nature. In other words, the taper helps to reduce an athlete’s physiological fatigue as well as their psychological and emotional fatigue. This shedding of fatigue allows improved performance to show up in competition. Why can’t one just rest completely when tapering? If an athlete were to take 1-2 weeks off of training leading into competition day, the athlete would be extremely well rested, but they would begin to lose fitness as fitness loss begins to occur within 7-14 days of complete rest. Therefore, the athlete needs to maintain most of their intensity and frequency they had prior to the taper to maintain their fitness and to stay “sharp” so that they don’t feel flat and sluggish come the day they need to perform. This is really where the art comes in as while an effective taper might look like an 8-14-day period of gradually reduced volume over time, the exact make-up of the day-to-day sessions is up to the coach and/or athlete. There are no secret workouts that must be included within a taper, it just needs to work for the athlete and make them feel confident and prepared to compete. This is much less a science and more of an art form. This is where coaching can get really difficult as there is no ”one size fits all” approach. Conclusions Let’s tie is all together here one final time. We know that a taper definitely works, and it is particularly important for athletes that are trying to peak for important competitions as there is research to suggest that an effectively designed and well-executed taper can improve performance by 2-3% on average. The best approach when designing a taper likely includes an 8-14-day taper consisting of a progressive (linear or exponential) reduction in training volume by ~40-60% of pre-taper loads, and maintenance of training intensity and frequency. I have summarized the research discussed above and some additional research literature not discussed above in a succinct table below that describes an evidence-based approach to a taper. Note that the taper variable manipulation is broken down by experience level of the athlete within the table, providing a more granular approach depending on the athlete’s experience level. This table can be incredibly useful for summarizing everything discussed herein as well as for a “quick reference” guide that you can print out and glance at when designing a taper for yourself or your athletes you work with. I hope you found this discussion of a rather complex topic both simple (as simple as a complex topic can be) and useful. Table 2. Optimal Tapering Prescription (1,3,5) References: 1. Bosquet L, Montpetit J, Arvisais D, & Mujika J. Effects of tapering on performance: A Meta-Analysis. Med Sci Sports Exerc, 2007. 2. Mujika, I., & Padilla, S. (2003). Scientific bases for precompetition tapering strategies. Medicine and Science in Sports and Exercise, 35, 1182–1187. 3. Pritchard H, Keogh J, Barnes, M, & McGuigan, M. Effects and mechanisms of tapering in maximizing muscular strength. Strength Cond J 37(2): 72-83, 2015. 4. Pyne DB, Mujika I, Reilly T. Peaking for optimal performance: Research limitations and future directions. Journal of sports sciences. 2009 Feb 1;27(3):195-202. 5. Wilson JM & Wilson, GJ, A practical approach to the taper. Strength Cond J 30(2): 10-17, 2008. Happy training and racing! -Ryan Eckert, MS, CSCS Do you enjoy our monthly educational content that we create? Not only do we create written content like what you just read, but we have a podcast too where the goal is also to share science-driven, evidence-based information highly relevant to endurance athletes and coaches. We do all of this for free, and we rely on the generous help and support of others to cover some of our basic operating costs for putting out this content. If you would like to help or support, the best way to do so is by becoming a Patreon supporter.
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