A summary of published research, not medical advice. See the Disclaimer.
Studies: every indexed trial and review on this topic, scored
Cold water immersion means sitting or standing in cold water, usually up to the chest or neck, for a few minutes. People do it after exercise or as a regular habit.
Best-supported effect: Faster return of muscular power after strenuous exercise in physically active adults. Probably helps a little (moderate evidence).
Most-cited weak claim: Better mood and lower stress from regular cold dips. Unclear: trials disagree (weak evidence).
How we grade evidence · Last reviewed: October 2026
What you need to know
In physically active adults, muscular power came back faster 24 hours after hard exercise with cold water immersion than with passive rest, with moderate evidence. Less soreness and feeling more recovered rest on small trials that could not be blinded, so the evidence is weak. In men doing resistance training, regular immersion after sessions may have made little or no difference to strength gains (weak evidence), and one 12-week trial found smaller muscle growth than with active recovery. Sudden cold triggers a reflex surge in breathing and heart rate, and reviews describe drowning, heart rhythm disturbances and cardiac arrest after sudden immersion, mainly in accidental immersion. Trials enrolled mostly healthy, active adults. Soreness results were best with water at about 10 to 15 °C for 10 to 15 minutes.
| Effect | Verdict | What was measured | Studied in |
|---|---|---|---|
| Faster return of muscular power after strenuous exercise | Probably helps a little (moderate evidence) Pooled analysis of 52 studies against simply resting, only days of follow-up |
Measured | Physically active adults, compared with passive rest |
A 2022 meta-analysis found that muscular power came back faster at 24 hours with cold water immersion than with passive rest [1]. Probably helps a little (moderate evidence): downgraded because outcomes were followed for only a few days after a single session and the comparison was passive rest only. Compared with other recovery methods, power recovery was similar [4].
| Effect | Verdict | What was measured | Studied in |
|---|---|---|---|
| Bigger strength gains from regular immersion after training | May make little or no difference (weak evidence) Two small trials in 37 men, neither showed bigger strength gains |
Measured | Men doing resistance training for 7–12 weeks |
| Lower muscle inflammation | May make little or no difference (weak evidence) Muscle sample trial in 9 men where each tried both, no better than active recovery |
Lab marker | Small group of active men after resistance exercise |
More on these results under Claimed but unsupported or contested.
| Claim | Verdict | What was measured | Studied in |
|---|---|---|---|
| Less muscle soreness after strenuous exercise | May help a little (weak evidence) Three pooled analyses agree, but trials were small, people knew what they got and rated it themselves |
Self-reported | Physically active adults after one hard session |
| Feeling more recovered after strenuous exercise | May help a little (weak evidence) People rated it themselves at 24 hours in small samples, participants knew what they got |
Self-reported | Physically active adults after one hard high-intensity session |
| Less soreness than other recovery methods (active recovery, contrast baths, warm water, cold-air cryotherapy) | May help (weak evidence) Pooled analysis of 28 studies, less soreness than most other methods, self-rated and not blinded |
Self-reported | Physically active adults after one hard session |
| Strength recovery compared with cold-air cryotherapy | May make it worse (weak evidence) Same pooled analysis, cold-air cryotherapy restored strength and 1-hour power better |
Measured | Physically active adults after one hard session |
| Better mood, lower stress, better sleep | Unclear: trials disagree (weak evidence) Better sleep, unchanged mood, stress lower at one time point, few trials with random assignment |
Self-reported | Healthy adults, mixed protocols, few randomized trials |
Two meta-analyses that compared cold water immersion with passive rest found less soreness after hard exercise with immersion [1][2]. A broader meta-analysis of recovery methods also found less soreness with immersion [3]. In one of them the pooled benefit over passive rest was slight, and results were best with water at about 10–15 °C for 10–15 minutes [2]. Participants cannot be blinded to cold water, soreness is self-reported, and the trials were small. May help a little (weak evidence).
In the 2022 meta-analysis, participants rated themselves as more recovered 24 hours after high-intensity exercise with cold water immersion than with passive rest [1]. May help a little (weak evidence): the outcome is self-rated, the intervention cannot be blinded, and samples were small.
A 2023 meta-analysis of 28 studies compared cold water immersion with other recovery methods. Immersion beat the other methods for soreness and beat active recovery, contrast baths and warm-water immersion on most outcomes. It was similar to other methods for muscular power and flexibility, and cold-air cryotherapy beat it for strength and for power one hour after exercise [4]. This is one pooled analysis whose result depends on the comparison, not trials that contradict each other. Soreness: May help (weak evidence), because it is self-rated and people knew which method they got. Strength compared with cold-air cryotherapy: May make it worse (weak evidence), from a subset of the same analysis.
In a 12-week controlled trial in 21 physically active men, regular immersion after strength sessions led to smaller gains in strength and muscle mass than active recovery did [5]. A 7-week trial in 16 men found no difference in strength gains [6]. May make little or no difference (weak evidence): two small trials that agree, downgraded because they studied only 37 people, all men. The claim comes from the idea that faster recovery allows harder training, which these training trials did not bear out [14].
In a small crossover trial that took muscle biopsies, cold water immersion was no better than active recovery at reducing inflammation and cellular stress after resistance exercise [7]. Most support for the inflammation claim comes from blood markers; cold exposure was among the recovery methods that lowered them [3].
A 2025 meta-analysis of health and wellbeing outcomes reported lower stress about 12 hours after immersion, but not at other time points. It also reported better sleep quality and quality of life, but no change in mood [8]. The authors noted few randomized trials, small samples and widely varying protocols, and inflammation markers rose right after immersion and one hour later. A narrative part of the review reported fewer sick days among people who took cold showers. Pooled immune measures showed no short-term change, and long-term effects have not been tested in adequate trials [8]. Unclear: trials disagree (weak evidence).
Shown in humans
Shown only in animals or cells
None found.
Theory only
| Side effect | Verdict | How often vs placebo | Source | Studied in |
|---|---|---|---|---|
| Cold shock response (reflex surge in breathing and heart rate) | Probably happens (moderate evidence) Pooled analysis of 17 groups plus a general review, frequency not reported |
Not reported | [9][10] | |
| Heart rhythm disturbances, cardiac arrest | Unknown (very weak evidence) Reviews of mainly accidental immersion, plus one field study of 20 swimmers |
Not reported; in one field study, brief arrhythmias occurred at 0.12 vs 0.037 per hour during vs outside immersion (not significant) | [9][10][16] | |
| Smaller muscle growth with regular immersion after strength training | May happen (weak evidence) Two small trials in 37 men, muscle fibres grew less with cold water |
Type II fibre size +17% with active recovery vs no significant increase with immersion (12-week trial) | [5][6] | 37 men |
| Anaphylaxis in people with cold urticaria | Unknown (very weak evidence) Reports of single patients only, a series of 21 children plus a review of published research |
Case reports only | [17] | People with cold urticaria |
Cold shock is a recognized cause of drowning in accidental immersion, and the reduction in the response after repeated immersions probably holds (moderate evidence) [9][10]. Longer immersion can lead to hypothermia [9]. The muscle growth finding is downgraded twice, for a small total sample and for studying only men [5][6].
This lists what studies and labels report. A pharmacist or prescriber can say whether it applies to a specific person.
This lists what studies and labels report. A pharmacist or prescriber can say whether it applies to a specific person.
| Combined with | What happened | Verdict | Source | Studied in |
|---|---|---|---|---|
| Beta-blockers (propranolol, metoprolol) | In 17 healthy volunteers, both drugs blunted the heart rate rise during 6 minutes of foot immersion in 5 °C water; the blood pressure rise and drop in forearm blood flow were unchanged | May happen (weak evidence) One study in 17 healthy volunteers who tried each option, foot immersion only |
[18] | 17 healthy volunteers |
No other interactions with drugs or supplements are documented in the studies found for this article.
These are the amounts used in the studies. They are not recommendations.
Recovery trials immersed participants after a single bout of exercise, with water temperature and duration varying between trials; soreness results were best at about 10–15 °C for 10–15 minutes [2]. The training trial that found smaller muscle gains used 10 minutes of immersion after each of two weekly strength sessions for 12 weeks [5]. The 7-week trial used 15 minutes at 10 °C after each of three weekly sessions [6]. Health and wellbeing trials used water at 7–15 °C for 30 seconds to 2 hours, mostly in baths [8]. The cold shock response diminished after about four repeated immersions, with variation between studies [10].