Benefits of exposure to extreme cold — voluntarily — 'very limited,' says researcher

Joe Costello, who has researched the use of cryotherapy, joined CBC Radio's Morning Edition to discuss the practice, which involves subjecting people to extreme cold for short periods of time to treat ailments.

Clinics claim cryotherapy helps with aging, wrinkles, rheumatoid arthritis

Cryotherapy clinics and manufacturers of cryotherapeutic tools claim the cold can help with muscle soreness and other ailments. (CBC)

A researcher says evidence is "very, very limited" when it comes to the benefits and safety of cryotherapy.

The practice of exposing people to extreme cold temperatures for short periods of time dates back to the ancient Greeks.

It is not a new concept but has become popular in recent years, with cryotherapy clinics opening up across the world. Claims have been made by manufacturers of cryogenic tools and the clinics that use them that the practice could help treat things such as muscle soreness, rheumatoid arthritis and even aging and wrinkles. 

Joe Costello, a lecturer at the University of Portsmouth in England, studied the use of cryotherapy to reduce muscle soreness in particular.

"We concluded that there is simply not enough evidence to categorically say if this treatment is or is not effective to reduce muscle soreness after exercise."

During whole-body cryotherapy, people will typically be exposed to temperatures of –60 C for 30 seconds in a pre-cooling chamber. From there, people will move into the cryotherapy chamber where they will be exposed to temperatures of –110 C or lower for a duration of two to three minutes. 

For reference, the coldest temperature ever recorded on Earth was –89 C, in Antarctica. 

Those who decide to undergo the treatment typically strip down to their underwear, save for some precautions when they enter the chamber, such as sandals or wooden clogs, doubling up on socks, gloves and something to cover the ears and face, if necessary. 

Joe Costello said trendy methods such as cryotherapy often 'trickle down' from professional and elite athletes to recreational athletes. (The Associated Press)

Costello tried it for himself.

"There's a cascade of physiology that occurs when your body experiences that extreme cold," he said. "You get an increase in your breathing; your skin cools rapidly," he said. "It's quite an unusual experience and rather hard to describe but I can assure you it's very cold."

A single session could cost as much as $60.

Costello said it's not uncommon for people to dish out money for a therapy that isn't fully understood. 

Trends and methods in use by professional athletes will trickle down to recreation athletes, he added.

"I would advise people to be careful in the extreme cold conditions," he said. "Make sure outside time ... is kept to an absolute minimum."

With files from CBC Radio's Morning Edition