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.
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!
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
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