Is Treatment With Cryotherapy Harmful?

Questions about whole-body cryotherapy rages on.

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In October 2015, the manager of a cryotherapy clinic in Las Vegas decided to self-treat after closing shop.  She was alone, and her treatment was unsupervised.  The next day she was found frozen solid. 

To be sure, what happened to this spa worker is an unfortunate abberation. Lots of athletes and patients alike swear to the benefits of cryotherapy. Nevertheless, the use of cryotherapy is unregulated, and we know little about either its benefits or its possible adverse effects.

 

Please note that in this article, I use the terms cryotherapy and whole-body cryotherapy interchangeably; however, cryotherapy also refers to a local treatment used by dermatologists.

What Is Cryotherapy?

Cryotherapy takes the traditional ice bath to a whole other level. Cryotherapy is like the opposite of spending some time in the sauna.

In the 1970s, Japanese researchers first developed cryochambers which used either liquid nitrogen or refrigerated cold air to achieve temperatures below 100 degrees Celsius (-212 degrees Fahrenheit)--way colder than any natural environment found on earth. By the 1980s the intervention made its way to Europe, and during the past decade cryotherapy spas have been popping up in the U.S. and Australia.

Before entering a cryotherapy chamber, a person strips down to her skivvies and is dried of any sweat.  The treatment lasts about two to three minutes. A person undergoing cryotherapy can receive one or two treatments on the same day or have treatments spread out over a span of several days.

What Does Cryotherapy Do?

Although touted as a potential treatment for various afflictions, cryotherapy is used for two main purposes: (1) to treat delayed muscle onset soreness resulting from exercise-induced muscle damage and (2) to treat inflammation and soreness caused by chronic diseases such as rheumatoid arthritis, multiple sclerosis, fibromyalgia and ankylosing spondylitis.

Delayed-muscle onset soreness is hypothesized to result from mechanical disturbances in the muscle membrane which evoke swelling, inflammation and free radical formation. This soreness peaks one to four days after exercise. Furthermore, experts believe that in the long-run, delayed muscle onset soreness can lead to decreased muscle length, decreased muscle force and decreased flexibility or range of motion.

Although we have no idea exactly how cryotherapy works, scientists hypothesize that it has a few specific effects. First, cryotherapy may decrease muscle metabolism by constricting the blood vessels feeding muscle. Second, cryotherapy may calm the sympathetic (fight or flight) nervous system and slow nerve conduction as well as increase parasympathetic response.Third, cryotherapy may mitigate the release of inflammatory mediators and creatinine kinase, a product of muscle breakdown. Finally, cryotherapy likely exerts a psychological effect that results in pain relief. Moreover, experts in the field claim that cryotherapy sessions result in the release of endorphins.

Does Cryotherapy Have Any Adverse Effects?

Just as we don't understand how cryotherapy works, we don't know if it has any adverse effects. However, limited and low-power research on the subject suggests that when performed in a supervised setting and for very short periods of time (two to three minutes), cryotherapy is safe.  Obviously, if performed for long periods of time without supervision—as happened with the cryotherapy worker in Las Vegas—hypothermia and death result. 

In addition to hypothermia, some other proposed adverse effects of cryotherapy include frostbite, skin burn, dizziness, loss of balance and increased blood pressure.

Ultimately, whole-body cryotherapy, like any extreme cold exposure, can be harmful when performed without supervision or for too long.  However, when performed for short bursts of time under supervision, cryotherapy is probably safe. Nevertheless, it's still unclear whether cryotherapy actually does anything.

Sources

Review article titled "Whole-Body Cryotherapy in Athletes" by G Banfi and co-authors published in Sports Medicine 2010.  Accessed on 11/5/2015.

Cochrane review titled "Whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults: by JT Costello and co-authors published in 2015.  Accessed on 11/5/2015.

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