Whole-body cryotherapy is a relatively new spin on the ice baths athletes have used for years in attempts to shorten recovery time from strenuous exercise. Traditional ice baths are chilling 10-minute dips into tubs filled with frigid water and ice in hopes of reducing inflammation, pain, muscle soreness, or swelling resulting from punishing exercise. Whole-body cryotherapy takes a lot less time – two to three minutes is the limit. You are encased in a refrigerator-like device with temperatures way below zero - about minus 166 Fahrenheit. This is so cold that lingering longer than three minutes (if you could stand it) would likely cause serious bodily injury. While researching this subject, I came across repeated accounts of track star Justin Gatlin developing frostbite on his feet because he entered a cryotherapy chamber wearing damp socks, which instantly froze to his skin. I also learned that cryotherapy is being offered as a spa treatment, promoted for toning the skin, invigorating the mind, improving sleep, helping reduce cellulite, managing chronic pain, and reducing stress and anxiety. I have seen no evidence that any of this is possible.
Based on what I've read, many athletes seem to relish an after-exercise chill, whether in the form of ice baths or cryotherapy chambers, because they believe that by cutting short any damaging physical effects of strenuous exertion they will be able to resume training sooner than would otherwise be possible. However, there is not a lot of research on the effectiveness of either method. The studies that have been done are contradictory – some have found no recovery advantage for ice baths or cryotherapy and some have shown slight improvements.
With cryotherapy, you first enter a chamber that is extremely cold – minus 76 degrees Fahrenheit – to get a feel for the freezing temperatures you will encounter a few seconds later when you step into the main chamber. While there, you must move constantly, waving your arms, wiggling your fingers and stamping your feet to keep your circulation going. You wear only a bathing suit or shorts, several layers of gloves, dry socks, a headband to cover your ears, and a face mask to protect your nose and mouth.
I visited one cryotherapy website to check the "contraindications," the health problems that would rule out a foray into the deep freeze. There was a long list of these, ranging from untreated high blood pressure, skin infections, diabetes and pregnancy to seizure disorders and various heart problems. Professional athletes, elite runners and others who participate in competitive sports usually are in superlative shape and may benefit from occasional ice baths or cryotherapy. If you're not one of those, I urge you to be wary of either practice until we have more and better evidence of the benefits and risks.
Andrew Weil, M.D.