How hot baths, steam baths, and hot water immersion affect recovery and performance for running, OCR, and endurance sports
Thomas Solomon, PhD.
Updated onReading time approx 7 minutes (1500 words).
What you’ll learn:
Hot water immersion means soaking in hot water after training. Contrast water therapy means bouncing between hot and cold water. Both are popular with runners, marathoners, trail and ultra folks, and people who do obstacle course racing (OCR) and enjoy suffering for fun.
If your main goal is faster recovery (less soreness, less fatigue, quicker “legs feel normal again”), post-exercise hot water immersion is unlikely to help much compared with other options.
Contrast water therapy might reduce delayed onset muscle soreness (DOMS) a bit, especially compared with doing nothing… but the evidence base is kinda messy.
Separate point, but important: doing regular post-exercise hot water immersion can help you acclimate to heat, which might help performance in hot races.
Curious about the how and why? Scroll down for the details, the nuances, and the nerdy bits.
The information I provide is not medical advice. Before making any changes to your habits of daily living based on any information I provide, always ensure it is safe for you to do so and consult your doctor if you are unsure.
What is hot water immersion?
Lots of people love a good soak. After the closing miles of a long winter run, my brain basically stops doing maths and starts doing bubble-bath logistics: How high can I stack the bubbles before physics calls the police? Warm water feels calming, and that alone can be valuable.
And yes… I’ve got a formative memory from my 1980s footballing years. When the FA Cup rolled around, I was dazzled by the post-match dressing-room celebrations. But the thing that got permanently burned into my neurons was the bathtubs. It was totally normal (and occasionally televised) for 11 grown men to pile into a single tub after a muddy match. I asked coaches, parents, teammates: “Why do they do that?” My favourite answer came from my Irish-accented Grandad: “They just fecking love it, Tommy boy.” My tiny 8-year-old brain decided it was just the fastest route to getting clean before dinner.
But there’s a serious question hiding under the foam: does soaking in hot water after exercise actually speed recovery, reduce soreness, or help you perform better next time? Let’s look at what the research actually says (and what it doesn’t).
What is the scientific evidence on the effect of hot baths, steam baths, and hot water immersion on recovery and athletic performance?
Quick note: I’m talking about recovery from training sessions and races. None of the studies I mention here are about recovery from injury, illness, or disease. And while hot water immersion can be used to help heat acclimation, I’m not going deep into that here (you can go full nerd on that in my heat acclimation article at veohtu.com/heat-3-howtoheatacclimate).
In hot water immersion studies, people usually soak for about 15 to 25 minutes in water around 35 to 45°C (95 to 113°F).
Most experiments compare hot water immersion with cold water immersion, contrast water therapy (hot and cold), or both. Some studies also compare it with passive recovery (rest), active recovery (light jogging or easy cycling), or other forms of recovery wizardry.
Although a meta-analysisA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. of post-exercise “heat therapy” reported a benefit for reducing soreness, it combined hot water immersion with other heat approaches (like local heat packs, infra-red phototherapy, and sauna). The authors also flagged a lack of high-quality studies and said more research is needed.
At the time of writing this section, there is no meta-analysis that focuses specifically on hot water immersion for recovery. The available individual studies (here, here, here, and here) suggest that hot water immersion probably does not meaningfully reduce delayed onset muscle soreness (DOMS) or feelings of fatigue when compared with cold water immersion, contrast water therapy, or just resting. Even without a systematic review, a 2018 narrative reviewA narrative review describes an entire body of evidence to summarise what is known on a topic. However, instead of using a systematic approach, a narrative review takes a subjective approach that allows the author(s) to express their opinion on the topic. from McGorm et al. (here) sums up the same overall vibe pretty well.
More recent work (published in 2020) found that hot water immersion during recovery from a single bout of resistance training did not further increase muscle protein synthesis or boost how much dietary amino acid got built into muscle in young people. So the popular idea that “heat after lifting means more hypertrophy” is not looking very credible. More likely, the heat-driven blood flow makes muscles look pumped and massive… which is fun, but not the same thing as building new tissue.
Bottom line: if you jump into a warm bath after a session, it probably won’t give you a magical recovery boost, but it also probably won’t hurt. The main common-sense caveat is body temperature. Your core temperature rises during exercise and needs to come down again so you can recover and stay healthy. So be sensible: use warm baths when you want rest and relaxation, when you’re cold after a grim session, or if you’re intentionally using hot water as part of a heat acclimation strategy for an upcoming race.
What is the scientific evidence on the effect of contrast water therapy (intermittent hot and cold) on recovery and athletic performance?
In contrast water therapy studies, people switch between cold water (about 10 to 15°C; 50 to 59°F) and hot water (about 35 to 45°C; 95 to 113°F). Time ratios usually land somewhere between 1:1 and 3:1 (cold:hot or hot:cold, depending on the protocol).
Right now, there’s not enough research to confidently say what the “best” temperatures, soak durations, or time ratios are.
A meta-analysis by Bieuzen et al. (2013) found that contrast water therapy reduced markers of exercise-induced muscle damage and reduced soreness compared with passive recovery (rest) and hot water immersion. However, contrast water therapy did not beat other recovery options like active recovery or cold water immersion.
That review also looked at performance outcomes and suggested contrast water therapy may slightly improve the recovery of muscle strength, but not muscle power, compared with passive recovery or hot water immersion.
Important warning label: the authors said most of the included studies were low quality and many had a high risk of biasRisk of bias in a meta-analysis refers to the potential for systematic errors in the studies included in the analysis. Such errors can lead to misleading/invalid results and unreliable conclusions. This can arise because of issues with the way participants are selected (randomisation), how data is collected and analysed, and how the results are reported., which makes the overall conclusions less certain. They wrote: “Overall the study quality in this review was low. The majority of studies had a high risk of bias making the validity of most of the results uncertain.”.
Can hot baths, steam baths, hot water immersion, and/or contrast water immersion enhance recovery and athletic performance?
Post-exercise hot water immersion is unlikely to improve recovery from exercise in any meaningful way.
Contrast water therapy is somewhat likely to reduce exercise-induced soreness, with a moderate effect sizeA standardized measure of the magnitude of an effect of an intervention. Unlike p-values, effect sizes show how large the effect is and indicate how meaningful it might be. Common effect size measures include standardised mean difference (SMD), Cohen’s d, Hedges’ g, eta-squared, and correlation coefficients.. It’s not a superhero, but it might be a decent side character.
Heat acclimation angle: regular post-exercise hot water immersion is likely to induce heat acclimation, which could potentially improve performance in hot conditions (go deep on heat acclimation at veohtu.com/heatacclimation).
Across the limited studies available, effects look broadly similar in trained and untrained participants, and in males and females. But, because the evidence is sparse, these comparisons are uncertain. Also, more research is needed in females because women are underrepresented in this field.
Keep in mind: there is high heterogeneityHeterogeneity shows how much the results in different studies in a meta-analysis vary from each other. It is measured as the percentage of variation (the I2 value). A rule of thumb: if I2 is roughly 25%, that indicates low heterogeneity (good), 50% is moderate, and 75% indicates high heterogeneity (bad). High heterogeneity means there’s more variability in effects between studies and, therefore, a less precise overall effect estimate. (variability) in study methods and results, a high risk of biasRisk of bias in a meta-analysis refers to the potential for systematic errors in the studies included in the analysis. Such errors can lead to misleading/invalid results, and unreliable conclusions. This can arise because of issues with the way participants are selected (randomisation), how data is collected and analysed, and how the results are reported., and possible publication biasPublication bias in meta-analysis occurs when studies with significant results are more likely to be published than those with non-significant findings, leading to distorted conclusions. This bias can inflate effect sizes and misrepresent the true effectiveness of interventions, making it crucial to identify and correct for it in research.. So, the overall certainty of evidenceCertainty of evidence tells us how confident we are that the published results accurately reflect the true effect. It’s based on factors like study design, risk of bias, consistency, directness, precision, and publication bias. Low certainty means more doubt and less confidence, and that future studies could easily change the conclusions. High certainty means that the current evidence is so strong and consistent that future studies are unlikely to change conclusions. is lowA low quality of evidence means that, in general, studies in this field have several limitations. This could be due to inconsistency in effects between studies, a large range of effect sizes between studies, and/or a high risk of bias (caused by inappropriate controls, a small number of studies, small numbers of participants, poor/absent randomization processes, missing data, inappropriate methods/statistics). When the quality of evidence is low, there is more doubt and less confidence in the overall effect of an intervention, and future studies could easily change overall conclusions. The best way to improve the quality of evidence is for scientists to conduct large, well-controlled, high-quality randomized controlled trials.. Therefore, additional high-quality randomised controlled trials are needed to increase confidence in the effect sizes reported in meta-analysesA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment..
How to use this: If you love hot baths, use them for relaxation, warmth, or as part of a planned heat-acclimation block, not because you expect a guaranteed recovery boost. If soreness is your main issue, contrast water therapy is the better bet versus doing nothing, but don’t expect miracles. Keep the doses sensible (don’t cook yourself), and drink to thirst — especially if you’re doing this after hard sessions or in a warm environment.
Information you can trust. All content on Veohtu is meticulously researched and written by Thomas Solomon, PhD. He does not sell supplements, recovery products, or ad space, and he has no sponsorships, brand affiliations, or ambassador roles. Everything you read reflects his independent views, shaped solely by peer-reviewed scientific evidence — and that will never change.
Full list of meta-analyses examining hot baths, steam baths, and hot water immersion for recovery
Here are the meta-analyses I've summarised above:
Effects of Post-Exercise Heat Exposure on Acute Recovery and Training-Induced Performance Adaptations: A Systematic Review. Ahokas et al. Sports Med Open. 2025
The effect of post-exercise heat exposure (passive heat acclimation) on endurance exercise performance: a systematic review and meta-analysis. Solomon and Laye. BMC Sports Sci Med Rehabil. 2025
Heat and cold therapy reduce pain in patients with delayed onset muscle soreness: A systematic review and meta-analysis of 32 randomized controlled trials. Yutan Wang, Sijun Li, Yuanyuan Zhang, Yanru Chen, Fanghong Yan, Lin Han, Yuxia Ma. Phys Ther Sport. 2021
An Evidence-Based Approach for Choosing Post-exercise Recovery Techniques to Reduce Markers of Muscle Damage, Soreness, Fatigue, and Inflammation: A Systematic Review With Meta-Analysis.
Dupuy O, Douzi W, Theurot D, Bosquet L, Dugué B. Front Physiol. 2018
Contrast water therapy and exercise induced muscle damage: a systematic review and meta-analysis.
Bieuzen F, Bleakley CM, Costello JT.
PLoS One. 2013
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Who is Thomas Solomon?
My knowledge has been honed following 20+ years of running, cycling, hiking, cross-country skiing, lifting, and climbing, 15+ years of academic research at world-leading universities and hospitals, and 10+ years advising and coaching in athletic performance and lifestyle change.
I have a BSc in Biochemistry, a PhD in Exercise Science, and over 90 peer-reviewed publications in medical journals.
I'm also an ACSM-certified Exercise Physiologist (ACSM-EP), an ACSM-certified Personal Trainer (ACSM-CPT), a VDOT-certified Distance Running Coach, and a UKVRN Registered Nutritionist (RNutr).
Since 2002, I’ve conducted biomedical research in exercise and nutrition and have taught and led university courses in exercise physiology, active recovery, biochemistry, and molecular medicine.
And, with my personal experience of competing on the track (800m to 10,000m), the road (5 k to marathon), on the trails, and in the mountains, by foot, bicycle, cross-country ski, and during obstacle course races (OCR), I deeply understand what it's like to train and compete — I've been there, done it, and gotten sweat, mud, and tears on my t-shirt.
Disclaimer: I occasionally mention brands and products, but it is important to know that I don't sell recovery products, supplements, or ad space, and I'm not affiliated with / sponsored by / an ambassador for / receiving advertisement royalties from any brands. I have conducted biomedical research for which I’ve received research money from publicly-funded national research councils and medical charities, and also from private companies, including Novo Nordisk Foundation, AstraZeneca, Amylin, the A.P. Møller Foundation, and the Augustinus Foundation. I’ve also consulted for Boost Treadmills and Gu Energy on R&D grant applications, and I provide research and scientific writing services for Examine.com. Some of my articles contain links to information provided by Examine.com but I do not receive any royalties or bonuses from those links. Importantly, none of the companies described above have had any control over the research design, data analysis, or publication outcomes of my work. I research and write my content using state-of-the-art, consensus, peer reviewed, and published scientific evidence combined with my empirical evidence observed in practice and feedback from athletes. My advice is, and always will be, based on my own views and opinions shaped by the scientific evidence available. The information I provide is not medical advice. Before making any changes to your habits of daily living based on any information I provide, always ensure it is safe for you to do so and consult your doctor if you are unsure.