How can contrast therapy improve sleep?

Contrast therapy can significantly improve sleep by helping to reset the circadian rhythm and enhance relaxation. Rhonda Patrick shared her experience where contrast therapy completely reset her circadian rhythm, allowing her and her husband to fall asleep earlier than usual, which was not typical for them 1.

Contrast therapy involves alternating between warm and cold temperatures. Ray Cronise explains that performing contrast showers—10 seconds of warm water followed by 20 seconds of cold water, repeated ten times and ending on cold—can help facilitate this. The process helps to make you alert in the morning and promotes sleepiness at night due to the effects on circadian rhythms and possibly due to increased norepinephrine levels 2.

Cronise also mentions that this practice can induce a profound level of relaxation, contributing to better sleep quality. He highlights a personal routine involving contrast showers about an hour before bed, transitioning immediately to a low-light environment, which can significantly improve sleep by helping lower core body temperature—an essential aspect regulated by melatonin 3.