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.
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.
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
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