Cryogenics while you’re alive: test run or arctic training?

What does subjecting the body to sub -100°C temperatures actually do to the body – and is there a place for it in athletes’ training regimes?
Review by Associate Professor Mike Climstein PhD & Joe Walsh

Title: Whole-body cryotherapy in athletes: From therapy to stimulation
Authors: Dr’s Lombardi and colleagues. (Laboratory of Experimental Biochemistry and Molecular Biology, Italy)
Source: Frontiers in Physiology (2017) 8 (258): pp1-16. Click HERE to read. Cochrane review available free HERE.

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Introduction: Many decades ago I competed in Olympic weightlifting. Being both a ‘wannabe’ athlete and an academic, I had heard that the Eastern Block Olympic lifters and athletes were doing ‘contrast baths’ of extreme heat and cold to facilitate recovery. As a lifter, I knew that the most important strategies were to train at the highest intensity just under the injury threshold (like I knew where that threshold was: I subsequently suffered a herniated L5/S1) and to facilitate recovery, because doing so would enable higher intensity training the next day, which would result in greater strength gains.

As there was no internet back then, I could only find very limited information in the library, so had to guesstimate what the protocol should be. I did, however, have a good understanding of physiology, specifically the mechanism of vasodilation (increased blood vessel diameter from the hot water exposure) and vasoconstriction (decreased blood vessel diameter from the cold water exposure), which should, I theorised, facilitate removal of muscular waste products from training and hence facilitate recovery. Given it was near whole body exposure via conduction (very effective for heating and cooling) I knew this should maximise the effectiveness of the contrast therapy. Being naïve (and that’s wording it nicely) I simply figured that I should use the hottest water I could tolerate for near full body submersion followed immediately by full body submersion in the coldest temperature I could tolerate (i.e. a combination of ice and water should equal 0°C, plenty cold enough). So perhaps I was one of the first to develop whole-body contrast therapy…

In their review of studies into cryotherapy (extreme cold treatment) since 2010, Lombardi and his colleagues state that there are a number of accepted contraindications to whole-body cryotherapy, which include cold intolerance or hypothermia, Raynaud’s disease, hypothyroidism, respiratory disorders, cardiovascular diseases (unstable angina, Stage III or IV heart failure) certain neuropathies, local blood flow disorders, cachexia (weight loss and muscle atrophy) and claustrophobia.

The whole-body cryotherapy procedure requires the participant to be minimally dressed (e.g. bathing suit and socks) upon entering the chamber. It is also recommended that a surgical mask be worn in order to avoid direct exhalation of humid air, and that the participant should not be sweating, as this can pose a risk of skin burns and tissue necrosis (death of tissue). There were no studies investigating benefits to muscular strength, muscular endurance or changes to body composition (body fat).

Lombardi and his colleagues did report on positive findings on whole-body cryotherapy on lipid profiles. One study, which involved active males who underwent 5, 10, or 20 whole-body cryotherapy sessions, found the following:

  • 5 sessions of whole-body cryotherapy had no effect on the lipid profile
  • 10 sessions of whole-body cryotherapy exposure resulted in a 34% decrease in triglycerides
  • 20 sessions of whole-body cryotherapy exposure resulted in 18.8% increase in high-density lipoproteins and a 15.2% decrease in low-density lipoproteins.

This literature review on cryotherapy noted that one study investigating the effect of moderate aerobic exercise combined with whole-body cryotherapy found no change in body weight or body fat percentage. Unfortunately, this study did not specify how many whole-body cryotherapy sessions the participants underwent. In another study with 10 professional tennis players undergoing whole-body cryotherapy (-120°C for 3 minutes) twice a day for five days, there was no change in resting metabolic rate or percentage of fat used as an energy source.

The authors concluded from these two studies that whole-body cryotherapy has a dose-dependent effect on lipids, and it did not appear to affect the resting metabolic rate.

The authors also investigated the effects of whole-body cryotherapy on bone health and found that it had beneficial effects on bone resorption to formation balance, suggesting that the increased osteogenic (bone formation) would be beneficial in the prevention of stress fractures and in post-fracture recovery.

Lastly, the authors concluded that whole-body cryotherapy was associated with improvements in muscular tiredness, pain, and wellbeing following strenuous exercise. They stated that whole-body cryotherapy exposure should be 20 sessions (minimum) and that 30 is considered optimum.

Pros: The authors have previously conducted a good volume of cryotherapy research themselves and provide a good overview of the literature currently available on whole-body cryotherapy. The authors did state the treatment effectiveness can be influenced by the participant’s body composition (i.e. body fat percentage).

These days, professional sports and the Australian Institute of Sport (AIS) have recovery centres with small pools and shower walk throughs which are hot and cold. The AIS also has recommendations for athletes (i.e. cold water exposure at 10°C), though to our knowledge AIS has not installed a whole-body cryotherapy chamber. However, some European soccer clubs are using them on a regular basis. Additionally, a number of high profile athletes in various sports are reportedly using whole-body cryotherapy to assist in performance (recovery, reduced injuries, energy, sleep) as are some celebrities. A 2015 Cochrane review concluded (at that time) there was insufficient evidence to support the use of whole-body cryotherapy for preventing and treating muscle soreness after exercise in adults, but we suspect given its increase in usage, new research studies will be able to provide greater insight into the actual benefits.

There is anecdotal information from the UK that whole body cryotherapy can reportedly burn between 500 and 800 calories in three minutes, though finding a published study to substantiate this claim has not proved possible. If this were an actual effect, it would be due to heat generation within the body to compensate for external cold. It is well known that shivering increases the body’s metabolism and hence caloric expenditure. We are currently unaware to what extent whole body cryotherapy increases metabolism, and for how long post-exposure: no doubt future studies will report this data. In the meantime, however, it would be advised to not rely upon these claims being correct until evidence exists to support them.

Cons: Unfortunately, at present, there is limited research available on the benefits of whole body cryotherapy.

With regard to adverse events associated with whole body cryotherapy, Carrard and colleagues (2017) published a case study involving a 63-year-old male who suffered transient global amnesia (loss of memory) after a single whole-body cryotherapy session. The man did recover completely within 24 hours. Camara-Lemarroy and colleagues (2017) published a recent case study of a 56-year-old who underwent whole-body cryotherapy experiencing an abdominal aortic dissection (i.e. tear in the aorta). It is not clear in these two cases, however, if the whole-body cryotherapy was causative or coincidental.

Associate Professor Mike Climstein, PhD FASMF FACSM FAAESS is one of Australia’s leading Accredited Exercise Physiologists and researchers. He is director of chronic disease rehabilitation at Vale Medical Practice.

Joe Walsh, MSc is a sport and exercise scientist. As well as working for Charles Darwin and Bond Universities, he is a director of Fitness Clinic in Five Dock, Sydney.