What is Cryotherapy? | Mark’s Daily Apple
Technically, “cryotherapy” refers to any method of using cold therapeutically. Icing a sprained ankle, freezing off a wart, or sitting in an ice bath after a game of Ultimate Frisbee are all forms of cryotherapy. Today, though, I’m using the term cryotherapy to refer specifically to whole-body and partial-body cryotherapy chambers.
Cryotherapy chambers use electric cooling or liquid nitrogen to expose users to super-chilled air in order to achieve various (supposed) benefits. The technology dates back to the late 1970s, and it used to be pretty niche, reserved mostly for top-level athletes and people with specialized medical needs. Now, cryo centers have popped up all over the place, and you can easily book yourself an appointment for any old reason.
Even if you’ve never visited one yourself, you can probably picture what I’m talking about here. A cryo chamber usually looks like a person-sized tin can that you stand up or lie down in, sort of reminiscent of polio-era iron lungs. You might go in with your entire body (whole-body cryo), or your head might stick out the top (partial-body cryo). Sometimes, though, a cryotherapy chamber is just a small room. The air inside isn’t just cold. It’s really, really cold, typically between -200 and -300 degrees Fahrenheit, or below -100 degrees Celsius. (You can also do targeted cryotherapy using a wand to blast a small area with cold air. I won’t be talking about that today because most research focuses on chambers.)
I’ve extolled the virtues of cold therapy before. Cold exposure is a simple and, I’d argue, adaptive way to fight inflammation, boost immunity, and build mental and physical fortitude. My modalities of choice are cold plunges and taking advantage of cold weather, but cryotherapy potentially offers many, maybe even all, of the same benefits.
The questions at hand today are whether cryotherapy chambers are worth trying and whether they offer anything special compared to other types of cold therapy.
How Does Cryotherapy Work?
When you go in for a cryotherapy session, you’ll strip down to only the bare essentials needed to protect your extremities and delicate bits (socks, shoes, or booties, gloves, underwear, and, if your head is in the chamber, ear covering and face mask). After a brief cool-down session, you step into the chamber. Due to the extreme temperature, the session will last only one to three minutes, never more than five minutes.
When exposed to very cold stimuli, several important things happen in the body:
- Vasoconstriction, which pulls blood toward the core and improves blood oxygenation and subsequent delivery of oxygen to muscles. When applied to an injured area, this prevents blood from pooling at the site and helps prevent secondary injury.
- Anti-inflammatory response, characterized by lower pro-inflammatory and higher anti-inflammatory markers.
- Analgesic effects to reduce pain.
- Lowered oxidative stress.
- Autonomic nervous system stimulation, or activation of the “rest-digest-repair” nervous system, as evidenced by changes in HRV and catecholamines (stress hormones).
None of these is unique to cryotherapy chambers. Any type of cold exposure elicits these effects. In fact, there’s some evidence that icing and cold water immersion do it better. Cold air simply isn’t as good at thermal conduction as ice or cold water.
It’s also worth noting that it’s not clear how long these effects last. Inflammation may go down acutely, for example, but we don’t have long-term studies to show that cryotherapy reduces chronic inflammation (the kind that causes more widespread, long-term health damage). In a study in which ten women did cryotherapy three times per week for three months, researchers observed immediate reductions in HRV right after the cold exposure. However, the women’s baseline HRV did not change from the beginning to the end of the study, meaning that the autonomic response was acute but not long-lasting.
Potential Cryotherapy Benefits
As with all forms of cold therapy, proponents make big promises about all the things cryotherapy can do. Here are three benefits for which there is enough evidence worth mentioning.
Recovery and injury prevention
The biggest reasons people seek out cryotherapy are for post-exercise recovery and treating sports-related injuries.
Overall, the studies in this area are mostly small and not always consistent, but most studies find that cryotherapy reduces pain and subjective fatigue following exercise. However, it doesn’t seem to attenuate muscle damage as measured by creatine kinase levels. Nor does it consistently improve performance.
Altogether, the evidence points to cryotherapy as being better for subjective recovery (how athletes feel) than objective markers of recovery.
Chronic pain reduction
A 2020 review found that =whole-body cryotherapy is effective at reducing pain in patients with osteoarthritis, fibromyalgia, rheumatic diseases like rheumatoid arthritis and ankylosing spondylitis disease, and other types of chronic pain. The protocols in these studies varied but generally entailed one or two sessions per day several times per week for a number of weeks.
A handful of studies have found that cryotherapy improves sleep in athletes:
- 7 professional male soccer players did cryotherapy or no cryotherapy (control) after a 90-minute training session. The men moved significantly less during sleep, a measure of sleep quality, following three minutes of cryotherapy. However, these same sleep improvements were not evident when they did only 90 seconds or two 90-second bouts with five minutes of rest in between.
- 22 young, fit men did a 55-minute run at 7 p.m., followed by three minutes of cryotherapy (at only -40 degrees) or three minutes of sitting quietly. Cryotherapy improved both subjective and objective sleep quality. Similar findings were reported with elite male and female basketball players.
- 10 female synchronized swimmers who were preparing for the Olympic trials did either three minutes of cryotherapy or no recovery (control) every day during two-week high-intensity training blocksy. Not only did the athletes sleep better following cryotherapy, but they also seemed to recover better from their workouts.
Obviously these findings are limited to highly fit individuals, but it’s possible that cryotherapy might work the same way for the average person.
Given the extreme temperatures, it’s important that you follow basic safety protocols. Go to a reputable place, never go more than a few minutes, and follow all the instructions to a tee. Don’t do cryotherapy without talking to your doctor if you have a heart condition, circulatory issue, or are pregnant.
The FDA put out a statement in 2016 letting everyone know that cryo is not FDA approved, for what it’s worth.
Pros and Cons of Cryotherapy
Given all this, here’s what I see as cryotherapy’s pros and cons.
- It’s quick. You only need to withstand a few minutes of extreme cold to reap the benefits.
- Although all cold therapy can be intimidating, I imagine that some folks will find the idea of a cryotherapy chamber easier than jumping into cold water.
- Cryotherapy seems pretty safe. (Hyperthermia and frostbite are possible, though.)
- It looks cool. Let’s be honest, standing in a cryo chamber with the liquid nitrogen gas swirling around you feels futuristic and kinda badass.
- It’s expensive compared to cold-water immersion, and there’s not good evidence that it’s any more effective.
- Cryotherapy studies are mostly small, and the results aren’t always consistent, possibly because different researchers use different protocols. Although I highlighted some of the probable benefits above, some studies also find no effects.
- Like any form of cold therapy, it’s not safe for everyone.
I wouldn’t discourage anyone from trying cryotherapy if they thought it might help them, but for now I’ll be sticking to my cold plunges.
I’m interested to hear about your experience with cryotherapy. Tell me in the comments if you used it and whether it helped. I’m especially interested to hear direct experiences comparing cold-water immersion to cryo chambers.
Take care, everyone.
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