Hot, cold, curious: what is contrast therapy?

Two temperatures, one ritual

You may have seen the routine: time in a sauna, followed by a cold plunge. In wellness settings, this is often called contrast therapy. In sports research, however, “contrast water therapy” usually means alternating between warm and cold water. That difference matters when interpreting the benefits.

What might it help with?

A systematic review of 18 trials found that contrast water therapy reduced post-exercise muscle soreness compared with passive rest. However, all included trials had a high risk of bias, and there was little evidence that it outperformed other recovery methods. Feeling less sore also does not necessarily mean that an injury has healed faster or that performance has fully recovered. Bieuzen and colleagues, 2013

A Cochrane review found some evidence that cold-water immersion alone reduced delayed-onset muscle soreness compared with rest. The studies were small and generally low quality, and the best method and safety profile remained unclear. Its searches were updated in 2011, so it should be read as an older piece of the evidence rather than a current consensus on sauna-and-plunge routines. Cochrane review

These findings do not establish an ideal sauna-to-cold-plunge sequence. They are also not grounds for promises about detoxification, immunity or guaranteed athletic gains.

Respect the cold

Sudden cold immersion can sharply increase breathing, heart rate and blood pressure. An involuntary gasp in water can be dangerous, and the cardiovascular strain is especially relevant for people with a cardiac history. Seek medical advice before attempting contrast therapy if you have heart or blood-pressure concerns. American Heart Association

There is no need to turn recovery into an endurance contest. A cold plunge is optional; gradual cooling after a sauna is a sensible starting point. Enjoyment and comfort matter more than chasing extreme temperatures. Harvard sauna precautions

Image: Winter swimming in Latvia by Rronis

Winter swimming in Latvia illustrates cold-water immersion generally; it is not a photograph of a verified sauna-and-plunge session.

Required credit: “Icehole Jurmala Latvia” by Rronis, via Wikimedia Commons, CC BY-SA 3.0. Downloaded at 1280 pixels wide; no crop or colour edits.

For general information only. Speak to a qualified healthcare professional about whether sauna or cold-water immersion is suitable for you.