Contrast Therapy: Alternating Hot and Cold for Recovery
Quick Intro
Contrast therapy alternates between hot and cold exposure, usually in water, with a few minutes in each. A typical version moves between a warm bath or shower and a cold plunge. It is used by athletes and recreational exercisers to reduce soreness after hard training. Related methods include cold-water immersion alone and sauna.
The Idea in Plain Terms
Heat widens blood vessels, and cold narrows them. Switching between the two is said to act like a pump, pushing blood and fluid through muscle and clearing waste from damaged tissue. Cold may also dull pain and reduce swelling.
The reasoning looks plausible. The difficulty is that the claim about flushing waste is not well supported, and next-day soreness does not come from waste products. Whatever help the method provides is more likely to come from reduced sensation of pain, the feeling of relaxation and the placebo effect, which is the benefit from simply expecting to feel better.
A typical protocol:
| Step | Detail |
|---|---|
| Hot | 3 to 4 minutes at about 38 to 40 degrees Celsius |
| Cold | 1 minute at about 10 to 15 degrees Celsius |
| Cycles | 3 to 5 rounds, ending on cold |
Protocol details vary a lot across studies and commercial programs.
A Worked Example
After a hard leg session, a person might do:
| Round | Hot | Cold |
|---|---|---|
| 1 | 3 minutes | 1 minute |
| 2 | 3 minutes | 1 minute |
| 3 | 3 minutes | 1 minute |
The total takes about 12 minutes and ends with cold. People with heart conditions or high blood pressure should speak to a doctor before using cold plunges.
What the Research Shows
A 2013 meta-analysis by Bieuzen, Bleakley and Costello in PLoS One pooled the available trials and found that contrast water therapy reduced delayed onset muscle soreness compared with passive rest, at 24 to 96 hours after exercise. Effects on other outcomes, such as strength, were less clear.
Dupuy and colleagues’ 2018 review of recovery methods also found that cold-water immersion and contrast water therapy reduced soreness in some analyses, and noted that the quality of the studies was variable.
There is a caution for people who lift to build muscle. A 2015 study by Roberts and colleagues in the Journal of Physiology had participants do strength training for 12 weeks, with some cooling their legs in cold water after each session. The cold-water group gained less muscle mass and strength than the group that did active recovery. Cold may blunt the signals that drive adaptation. This is one study with a specific protocol, and the result suggests avoiding regular cold-water immersion straight after strength sessions when the main goal is muscle growth.
Who It Suits
- Athletes with multiple events in a short time, where feeling less sore matters more than long-term adaptation.
- People who enjoy the sensation.
- Recreational exercisers seeking comfort, aware of the trade-off.
It is not advised for people with circulatory conditions, high blood pressure, cold sensitivity or heart problems without medical advice.
How to Use It
- Use water you can tolerate safely, never extreme temperatures.
- Keep cold exposures to a minute or two.
- End on cold if comfort allows.
- Use it after competition or in heavy blocks, and less often in phases focused on muscle growth.
- Do not use it on injured areas.
- Stop if you feel dizzy or unwell.
Common Misunderstandings
It is not flushing toxins.
It is not harmless to every goal. Cold may blunt strength gains.
It is not essential. Sleep and nutrition do more.
FAQ
Is a cold shower enough? Cold showers feel similar in ways, with less research behind them.
How cold is too cold? Below about 10 degrees Celsius adds risk without added benefit.
Does sauna help recovery? Heat may aid relaxation. Evidence for recovery is limited.
Should I do it before or after training? After, if at all.
Where This Comes From
Bieuzen F, Bleakley CM and Costello JT, 2013, contrast water therapy and exercise induced muscle damage: a systematic review and meta-analysis (PLoS ONE, 8, e62356). Roberts LA and colleagues, 2015, post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training (Journal of Physiology, 593, 4285 to 4301). Dupuy O and colleagues, 2018 (Frontiers in Physiology).
Related to: active recovery, sleep and recovery and supercompensation. Related reading includes foam rolling.