Cryotherapy sounds like something you sleep in on your way to Mars, but it is actually simply what you are doing when you ice a sore ankle, take a refreshing cold shower, or ice your hand after burning it on a hot stove. Simply put, it is the use of ice or cold as therapy.
Cryotherapy (from Ancient Greek κρύος meaning "icy cold, chill, or frost") is a recovery method that some pro athletes and biohackers use nearly every day. The benefits touted by cold exposure enthusiasts include faster recovery time, an enhanced immune system, increased cell longevity, decreased levels of inflammatory molecules (like interleukin 6), and, of course, an increased tolerance for exercising outdoors in the winter, especially north of the 49th parallel.
Aside from slapping an ice pack on a sore ankle after a misstep during a morning trail run, the majority of the population has never dunked themselves into a 20-minute ice bath or a hot-cold contrast shower, or stepped into a sci-fi looking cryotherapy chamber. Are they missing out on something amazing? Are you? Let’s take a look.
Does Cold Help with Pain?
A bunch of studies have come out recently that show the effectiveness of cold thermogenesis, icing, and cold water immersion. Let’s examine two of them. Both these studies looked at the effects of cold on decreasing muscle soreness, exercise-induced muscle damage, and inflammation.
The first study called The Effects of Multiple Daily Applications of Ice to the Hamstrings on Biochemical Measures, Signs, and Symptoms Associated With Exercise-Induced Muscle Damage, demonstrated that icing three times a day for 20 minutes at a time can assist with soreness. This is good news for anyone who has just started a workout program that has been leaving them feeling beat up and sore—but let’s put a pin in this notion for now. You may want to wait until you have read this entire article before you finish your squats and immediately slap on an ice pack.
In the second study, Acute Response to Hydrotherapy After a Simulated Game of Rugby, researchers found that rugby players who used two 5-minute cold water immersion sessions (ice baths) were able to significantly reduce soreness and the effects of muscle damage.
So, yes! Whether it is a cold shower, an ice bath, or some cold packs, you can break out the cold if you want to alleviate sore muscles.
Does Ice Help with Healing?
The Greek physician Hippocrates wrote about using cold therapy to control pain and swelling way back in the fourth century B.C., and the Roman physician Galen described using cold compresses for pain management on soft tissue injuries back in the first century A.D. Despite the long history of using ice for pain control, there are studies that are commonly cited in the argument against icing for healing.
If inflammation is the body’s natural way to heal an injury, why the heck would you want to stop this helpful inflammatory process?
When an injury occurs, your body creates inflammation as part of the natural healing response. So, the argument goes, if inflammation is the body’s natural way to heal an injury, why the heck would you want to arrest this helpful inflammatory process?
It has also been pointed out that icing has been shown to increase the permeability of lymphatic vessels (the tubes inside you that help carry excess fluids back into your cardiovascular system). The problem with that is, once this lymphatic permeability has been increased, there may be a risk of large amounts of fluid flowing back into the sore area. This could, in turn, cause even more swelling than before.
A study commonly cited that supports this argument is The Use of Cryotherapy in Sports Injuries, in which researchers conclude that “cold can inhibit inflammation as well as enhance inflammation.”
Also when ligament injuries were induced in pigs (a corollary to the type of injury you might get when weight training), the swelling was greater in the limbs that were treated with ice. But in the study (as well as in another study entitled Cryotherapy Influence on Posttraumatic Limb Edema) the chilly little animal subjects were iced for very long periods of time—up to one hour in length. That is well beyond what any sports doc would recommend you do on your sprained (or is it strained?) limb.
Another study that is commonly cited in the argument against icing is the 2008 study Is Ice Right? Does Cryotherapy Improve Outcome for Acute Soft Tissue Injury? This literature review of cryotherapy research concluded: “There is insufficient evidence to suggest that cryotherapy improves clinical outcome in the management of soft tissue injuries.” So the jury is definitely still out on this one.