The best coaches know that helping athletes recover efficiently encourages maximized performance in both training and racing. But recovery has come to mean much more than just resting. Assisted recovery has become all the rage amongst high-performers and consequently an entire industry has sprung up to feed the demand of athletes looking to enhance their recovery time. Assisted recovery speeds up the elimination of natural, cellular chemical build-up created by high level exercise, and restores the building blocks needed to resume those efforts as soon as possible.
What Options Do We Have for Cold Therapy Recovery?
Cold therapy in the form of cold water immersion or cold water circulation garments is among the recovery technologies on the forefront of the market. Several manufacturers make garments that can be worn on the legs or other parts of the body with attached pumps and tubing that circulate cold water at 5-10 degrees celsius. More simplistic designs, like incorporating reusable freezer packs in strategically located pockets, are also available at a much lower cost.
The most cost-effective method for cold water therapy is also the simplest: immersion. In order to achieve this at home, an athlete just needs to fill a tub with ice and water and settle in for a period of time. The experience is immediately invigorating, so it’s clear how athletes would seek to transfer the feeling from icy bathtubs into more portable cold garments. But just because something feels good doesn’t necessarily mean it’s scientifically effective.
What Are the Primary Cold Therapy Theories?
Many of the central theories behind cold water immersion recovery pertain to lowering core temperature. As core temperature increases with physical activity, adverse physiological effects arise in the central nervous system, the muscle cells, and the cardiovascular system. Cold water immersion lowers core temperature quickly and reverses some of the effects of body temperature elevation. That being said, in order to be effective, immersion temperature and duration need to be on the extreme side (5-10 degrees celsius and 20-30 minutes). This proves to be nearly unbearable and dangerous if done without supervision, and can still yield inconsistent results.
Cardiovascular Strain & Metabolite Clearing
Additionally, during high intensity exercise, metabolites such as lactic acid are produced and can build up in muscle cells. For optimal performance, these chemicals must be cleared before the muscles can return to peak action. Cooling has been theorized to enhance removal of metabolites and allow for more efficient restoration of a normalized intracellular milieu. Unfortunately, studies have found that the opposite is true—cooling is actually detrimental to muscle cell function, specifically in cases of anaerobic sprinting.
Other suggested benefits include the reduction of cardiovascular strain & metabolite clearing. When the body is overheated, cardiac output increases in order to boost blood flow to the skin for the dissipation of heat. With cold water immersion, blood vessels in the skin constrict, pushing blood volume back into central circulation reducing cardiac output. Some studies have verified that this occurs, but none have shown that immersion yields any physiological benefit or specific performance benefit.
Additional Cold Therapy Theories
Other studies on cold water immersion therapy have examined its impact on factors such as parasympathetic tone and the reduction of inflammation, soreness, and overall fatigue. However when it came to performance, results were either inconclusive or cold immersion was found to be no better than placebo. Across exercise physiology and sports medicine theorists, the consensus is becoming clearer: cold water immersion study participants might ‘feel’ better afterwards, but their performance didn’t consistently or significantly improve.
For coaches, I believe the message is fairly clear: cold water therapy in the form of immersion or cooling garments should be approached with a degree of caution. While this recovery adjunct may help athletes with subjective measures of muscle soreness and fatigue, performance has not been proven to be affected, and may even be negatively impacted. For this reason, if you have an athlete who is ready to purchase cold circulation garments or wants to jump in an ice bath after a tough training session, consider cautioning them about these methods. If they’re persistent, perhaps suggest a trial before they go all-in.