May 2020

Cold as ice

Ice baths are as common as weight rooms these days. But why are they used?

Cold therapy in one form or another has long been used in sport to treat injuries and to aid recoveries. Where it was once an ice pack on the knee though, cryotherapy has evolved into an entire industry aimed at ensuring athletes recover quickly and return to peak performance.

Rugby league is one of the most physically demanding sports on the planet. Each player can be involved in up to 50 collisions per match that carry as much force as a car crash.

Bumps, bruises and general soreness are par for the course from your local A grade player all the way through to the NRL. But where your local player might slap an ice pack on a bruise to accompany a beer at the pub, NRL players are using a variety of techniques to reduce soreness and recover from ever more intense matches.

Clubs have taken to installing ice baths in their performance centres while others have invested in cryotherapy – chambers of air cooled to minus 85 degrees that players stand in wearing just mittens, socks and underwear.

So just what does this cold therapy do and how does it benefit athletes?


Dr Jonathan Peake is a researcher in the School of Biomedical Sciences at the Queensland Institute of Technology and he says the use of techniques such as cold water immersion therapy (CWI) and cryotherapy assist in kick starting the recovery process for rugby league players.

“Ice baths can provide some short-term benefits for recovery. So if athletes need a quick turn around between training or competition, then ice baths are ok… One of the most commonly reported benefits of an ice bath is a decrease in muscle soreness.”

He does however qualify this, saying the benefits are often dependent on an athlete’s own perceptions as muscle soreness is different for every player and there has been little research into an objective measurement of muscle soreness.

“Most of the effects of ice baths are subjective and there is some suggestion they are not much more than a placebo (that is, athletes say they feel better after ice baths),” Dr Peake says.

A placebo effect though, isn’t exactly detrimental to an athlete’s health in this case. After all, if they feel better then there’s a chance they’ll train and play at a higher level.

The full mechanism of CWI or cryotherapy isn’t wholly understood. Researchers are yet to fully explain how ice baths and similar therapies work but Dr Peake says there is some understanding.

“By reducing muscle blood flow, icing is believed to reduce the movement of white blood cells (which cause inflammation) into muscle. Icing is also believed to reduce the rate of metabolic reactions in muscle, leading to less inflammation.”

Dr Peake’s research however, did indicate that athletes should be careful about the timing of their ice baths. It’s believed that prolonged uses of ice baths out of competition, when players are trying to build muscle, could reduce muscle growth, whereas ice baths in competition can assist in recovery and increasing muscular endurance.

“All of my work has focused on long-term effects with strength training and generally there is no long-term benefit in this context. However, there is some research reporting long-term improvements in muscle metabolism that might translate to better endurance performance. But there is not enough data to draw any definitive conclusions about this,” he says.

He added that the potential detriment to muscle strength may come from the ice restricting blood flow to the recovering muscles, slowing the recovery process. However, that’s not to say ice baths aren’t useful during the season.

“It probably depends on the phase of training athletes are in. If they are looking to build strength and muscle mass, then ice baths are probably not so good. But if they (are) in a maintenance or taper phase, with short periods between games, then there is likely no disadvantage with ice baths.”

While it appears the benefits of CWI on muscle soreness is up for debate, Dr Peake says the use of ice when it comes to injuries should remain part of the treatment protocol.

“If the swelling is the result of a more serious muscle tear, then ice baths are probably a good idea. It is important to consider treating muscle injuries differently from ligament or tendon injuries, because the composition and blood supply of these tissues are quite different. Using ice to treat ligament or tendon sprains/strains is still probably a good idea.”


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