Alternating hot and cold water eased soreness more than rest did in a review of 18 small trials
The 2013 PLoS One meta-analysis pooled 18 trials of contrast water therapy after hard exercise. It found little evidence that contrast beat cold water alone or the other active recovery methods it looked at.
The paper
Contrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-Analysis
Bieuzen F, Bleakley CM, Costello JT. PLoS ONE, 2013;8(4):e62356.
See the study at a glance
- Design
- Systematic review and meta-analysis
- People
- 18 trials, 356 people
- Who they were
- Healthy people aged 14–36 in trials published up to February 2013. Of the 356 participants, 301 were men.
- What they did
- People alternated between hot water at 35.5–45°C and cold water at 8–15°C within an hour of exercise. Hot bouts lasted 1–3 minutes, and most cold bouts in the review's tables lasted 1 minute.
- How long
- From under 6 hours to more than 96 hours after exercise
These numbers came out of it
−0.51
Across 13 trials, contrast baths beat passive rest on soreness at 24 hours. Reviews use this standardized unit to pool trials that scored soreness in different ways.
18 of 18
All 18 trials carried a high risk of bias. None kept participants in the dark about which recovery they got.
Not tested
Whether ending hot or cold mattered went untested. The review logged each protocol's last bath and never compared outcomes by it.
The researchers did this
The review pooled trials in which healthy people alternated between hot and cold water within an hour of exercise hard enough to damage their muscles. The hot water ran 35.5–45°C and the cold 8–15°C, usually in bouts of one to three minutes.Source 1 · Meta-analysisContrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-AnalysisBieuzen F, Bleakley CM, Costello JT. PLoS ONE, 2013.Read the paper ↗PubMed ↗
Compared with passive rest, contrast baths left people less sore at every point the trials checked. In standardized units the difference was −0.62 within 6 hours and −0.51 at 24 hours.Source 1 · Meta-analysisContrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-AnalysisBieuzen F, Bleakley CM, Costello JT. PLoS ONE, 2013.Read the paper ↗PubMed ↗ The 48-hour figure was −0.58 and the 72-hour figure −0.40. One trial that ran past 96 hours reported −1.21. Strength loss was smaller too.
The review found little evidence that contrast beat cold water immersion, warm water, compression, active recovery or stretching.Source 1 · Meta-analysisContrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-AnalysisBieuzen F, Bleakley CM, Costello JT. PLoS ONE, 2013.Read the paper ↗PubMed ↗ At 48 hours the benefit was larger when the hot water stayed below 40°C.
The review's table of studies notes whether each protocol started and finished hot or cold. It never analyzed outcomes by finishing temperature, so it can't settle whether ending on cold matters.Source 1 · Meta-analysisContrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-AnalysisBieuzen F, Bleakley CM, Costello JT. PLoS ONE, 2013.Read the paper ↗PubMed ↗
The study can't tell you these things
- Every trial carried a high risk of bias, and participants always knew which recovery they got.
- The trials were small, and 301 of the 356 participants were men.
- The outcomes were soreness and strength after exercise, so the review says nothing about heart health or metabolism.
- The hot half of every protocol was a water bath, and a sauna is a different kind of heat.
People quote it like this
Anyone who says alternating hot and cold beats either one alone won't find much support here. Contrast beat passive rest, and the review found little evidence that it beat cold water.Source 1 · Meta-analysisContrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-AnalysisBieuzen F, Bleakley CM, Costello JT. PLoS ONE, 2013.Read the paper ↗PubMed ↗
From our sister magazine
Sauna Monthly covers how to run hot and cold sessions at home
We cited these sources
- 01Bieuzen F, Bleakley CM, Costello JT. Contrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-Analysis. PLoS ONE. 2013;8(4):e62356. doi:10.1371/journal.pone.0062356 PMID 23626806