In the sports world and fitness industry, there is a perpetual search for a new edge. Athletes are always trying new sketchy supplements, workout programs, fitness gadgets, and sometimes experimenting with the borderline supernatural to gain an advantage. Over the last decade, cryotherapy has become extremely popular. Ice baths were once the exclusive domain of competitive athletes; now grandma is even doing it. What's more, is we found a way to do it without the torture of submerging ourselves in freezing water: it comes in form of the cryotherapy tank. It is all the rage. You stand in an expensive space-aged looking cylindrical tank while super cool air, 200 to 300 degrees below zero, is released all around your body for 2 to 3 minutes. Miraculously it does not kill you or give you frostbite (in most cases). It is supposed to help performance, recovery, and of course, weight loss. But does it?
FACT: Cold weather forces your body to burn more fat than hot weather. Both shivering and brown fat activity (BAT) increase your energy expenditure, causing you to burn more calories in cold temperatures.
Cold baths have been used throughout history to treat all sorts of ailments. Conditions that were believed to be treatable by cold immersion baths included: nightmares, leprosy, plague, rickets, inflammation of the eyes, 'female complaints,' hysteria, gout, constipation, blows to the head, numbness, bronchitis, cancer, and yes, even flatulence. Today it is widely believed that temporarily decreasing body temperature with a cold shower, bath, or cryotherapy tank is postulated to improve post-exercise recovery and boost performance via anti-inflammatory processes (however these mechanisms are not well understood). The data is unclear (inconclusive), whether such temperature manipulations actually have a positive effect. Yet it is clear, numerous cold therapy claims are plain hype and pseudoscience, while some other effects may actually be counterproductive.
Sad But True: In the 18th and 19th century cold baths were used in asylums for the mentally ill. Patients were physically restrained in a tub filled with ice water, held in place with a wooden or steel panel around the neck, and doused with streams of cold water. Vincent Van Gogh was subjected to this 'treatment' many times. Seems like an enhanced interrogation technique, otherwise known as torture.
Many of the justifications of cryotherapy tanks and therapeutic ice baths are bourne on the idea that icing helps injured tissue. Recently, Dr. Mirkin, who literally wrote the book on icing for injuries and coined R.I.C.E. (Rest, Ice, Compression, and Elevation), has revised his thinking. He now believes that ice and complete rest may impair the healing process:
When you damage tissue through trauma or develop muscle soreness by exercising very intensely, you heal by using your immunity, the same biological mechanisms that you use to kill germs. This is called inflammation. When germs get into your body, your immunity sends cells and proteins into the infected area to kill the germs. When muscles and other tissues are damaged, your immunity sends the same inflammatory cells to the damaged tissue to promote healing. The response to both infection and tissue damage is the same. Inflammatory cells rush to injured tissue to start the healing process (Journal of American Academy of Orthopedic Surgeons, Vol 7, No 5, 1999). The inflammatory cells called macrophages release a hormone called Insulin-like growth Factor (IGF-1) into the damaged tissues, which helps muscles and other injured parts to heal. However, applying ice to reduce swelling actually delays healing by preventing the body from releasing IGF-1
After these statements and others, there has been a growing anti-ice movement in therapeutic circles. The argument against ice tends to center around ice impeding the healing process as an ‘anti-inflammatory.’ Throughout the healing process (injury, inflammation, repair, remodeling), we need each of those stages to occur in order. Immediately after tissue damage, cells send out a chemical distress signal answered by several types of white blood cells, which arrive on the scene and trigger inflammation as they go about their work attacking pathogens and cleaning up and repairing the damaged cells. Icing, if done too long, may harm regeneration (FYI, this is not grounded in established science either!). The summary of much of the data on icing post-injury is that the research quality has been generally poor, and the outcomes tend to be inconclusive. On the other hand, the theory that ice impedes the normal healing response by limiting inflammation is not well documented in the literature. Most of the rationale for or against ice is based on limited research and data. What we do know is that it is one of the safest pain 'medicines' available.
Rule of Thumb: Ice an acute injury for approximately 5 minutes and talk to your doc. Apply heat on chronic injuries. Active recovery may be the best answer....move as soon as possible. Instead of R.I.C.E. use M.E.A.T. (Movement, Exercise, Analgesia, Treatment)
A Cochrane review – the gold standard in independent healthcare evidence – pooled the results of four studies and concluded there was insufficient evidence to support cryotherapy use to relieve muscle soreness after exercise.
There is insufficient evidence to determine whether whole-body cryotherapy (WBC) reduces self-reported muscle soreness, or improves subjective recovery, after exercise compared with passive rest or no WBC in physically active young adult males. There is no evidence on the use of this intervention in females or elite athletes. The lack of evidence on adverse events is important given that the exposure to extreme temperature presents a potential hazard.
More recent evidence shows cold water immersion and cryotherapy may inhibit hypertrophic responses in the body. Cold water immersion attenuates long term gains in muscle mass and strength. It also blunts the activation of key proteins and satellite cells in muscles up to 2 days after strength exercise! In other words, ice may be counterproductive to muscle adaptation. The current findings contribute to an emerging theme that cold water immersion therapy does not work better than a placebo and may, in fact, negate some positive effects of exercise and/or prolong the recovery process. Despite the growing evidence against this type of therapy, it is still being used in most professional athletic locker rooms worldwide. Top athletes and celebrities from LeBron James to Jennifer Aniston regularly use these therapies and swear to its usefulness. This is yet another reason we should not look toward athletes and famous people for health advice.
NOTE: There is NO good scientific evidence that a couple of minutes in a whole-body cryotherapy chamber will result in any long-term weight loss, confer anti-aging benefits, potentiate athletic performance or remove cellulite. Save your money and time. However, Cryolipolysis or CoolSculpting works. A systemic review of the literature shows it averages a 14-26% reduction of body fat in targeted areas. This procedure appears to be safe in the short term, with limited side effects. It is important to note that Cryolipolysis doesn’t target visceral fat, so it won’t improve your overall health.
There is an old saying in fitness circles: "You should train hard and recover harder!" According to the best evidence available, cryotherapy and cold water immersion do not help recovery and may impede progress. The best practices for recovery are still the tried and true ones of ensuring adequate active rest, eating properly, and learning how to regulate stress levels. As far as evidence-based modalities, massage therapy post-exercise outperforms most other recovery methods. Based on a 2018 meta-analysis that reviewed 99 studies comparing the effects of 10 different recovery methods (assessing DOMS, perceived fatigue, and markers of inflammation and muscle damage), massage therapy was generally found to be the most effective recovery modality.
The research for cold water immersion and cryotherapy tanks is unconvincing at best and potentially deleterious at worst. Save your time and money and go with more evidence-based strategies. For now, I'm going to leave the ice for my drinks and cold immersion for the Coney Island Polar Bear Plunge.