Is Cryotherapy worth the risk?

It’s hard to avoid the constant flurry of international Rugby Union matches at the moment, with the Rugby World Cup taking place in England this month.

Constantly reaching for the remote to turn the commentary up or flick over to watch Ainsley Harriott perform the Salsa will be enough physical activity for some on a Saturday evening, but not for the 600 elite players pushing their physical capabilities to the limits. They undergo grueling training regimes to prepare for intense games with sometimes as little as four days rest between matches.

An analysis in a 2009 journal by the Department of Physics and Astronomy at the University of Leicester found that “a dump tackle exerts a force akin to a 28mph car crash whilst a head-on collision exerts that akin to a 40mph car crash”. In the mathematical models used the rugby players were assumed to be running at 8m/s and weigh 100kg. This World Cup’s heaviest player, French prop Uini Atonio, weighs in at a whopping 145kg.

This is a lot for the human body to be put through and so the teams invest in state-of-the-art training and nutrition programmes to prepare and recover each individual player in the best way possible.

(Wales captain, Sam Warburton, doesn't look to be enjoying the mobile cryotherapy unit, photo: Ben Evans/Huw Evans Agency)

The Welsh Rugby Union have been taking this one step further for a number of years and invest in whole-body cryotherapy sessions to reduce the effects of delayed onset muscle soreness (DOMS) experienced after intense training and games. The name comes from the Greek words for “icy cold” and “cure”. Players are exposed to temperatures ranging from -110°C to -160°C in futuristic chambers for a few minutes by using refrigerated air or liquid nitrogen. To put this into context, weather observations at Casey Station on the coast of Antarctica reported temperatures of just below -13°C at the time of writing. Chilly.

The idea is that this speeds up the recovery process; in the same way you’d instantly reach for the bag of peas in the freezer if the kitchen cupboard door attacked your head. The lower temperatures reduce pain and swelling by narrowing blood vessels and reducing blood flow to the area.The quicker a player recovers, the quicker they can get back to training and prepare for the next game, which is of paramount importance in a tournament such as the World Cup. But does this work at all, and if so, how?

Whole-body cryotherapy has its origins in 1970s Japan as a method of treating rheumatoid arthritis to relieve inflammation. It tricks the brain into thinking that the body is freezing to death and flushes the circulatory system by constricting blood vessels towards the surface and redirecting blood to the internal organs. Cooling of the outer layer of skin also induces a rush of endorphins (endogenous morphine – the body’s natural opiates), reducing the perception of pain and producing a sense of euphoria.

Upon exiting the therapy chamber, surface temperature rapidly increases and blood vessels towards the surface dilate. The blood, fresh from filtration by the kidneys and oxygenation by the lungs, returns to the muscles and brings along a selection of ‘goodies’ with it; researchers reported an increase in anti-inflammatory and a decrease in inflammatory cytokines in the blood after cryotherapy. These are proteins that act as messengers between cells during inflammatory responses. In addition, the muscular enzymes creatine kinase (involved in the production of phosphocreatine, a high-energy molecule used during cellular processes such as those required for muscle recovery) and lactate dehydrogenase were positively affected; a victory for cryotherapy?

Cochrane, an independent network of health researchers and professionals aiming to collate separate studies, assessed four different reports and found that there was no evidence to suggest that cryotherapy is any more effective than passive rest in reducing soreness (although the studies did not assess elite athletes or females).

In fact, officials from the Welsh Rugby Union have acknowledged the lack of evidence for its effectiveness but said that the Union “thinks it works and that’s why we use it”. Captain Sam Warburton was reported to have returned from injury much quicker than expected after using the “evil sauna” treatment.

The Cochrane review highlights that there are risks associated with the treatment and that those plunging into sub-Arctic temperatures need to err on the side of caution. Its positive effects are unclear, and so the dangers also may not be fully understood. Those using cryotherapy should be thoroughly educated and trained as to avoid cases like 100m sprinter Justin Gatlin, who contracted frostbite in 2011 after going into a chamber in sweaty socks.

Levels of troponin I (a marker of cardiac tissue damage) were reported to be unchanged, suggesting that the heart is not adversely affected by cold stress. However, people with high blood pressure or heart problems are advised to avoid the treatment, as such an environmental stress could aggravate pre-existing problems.

Even if the physical benefits of whole body cryotherapy are still uncertain and the risks potentially serious, there’s no doubting the positive mental impact it will have on athletes. The weird and wonderful placebo effect could allow teams to train harder and more often, believing that they have a superior recovery regime. Come match day the players will think that they have an edge over their opponents, and confidence levels in the split-second before a tackle can make the difference between winning and losing a game, or a World Cup.

#GregorLawrence #Cryotherapy #Health