Joseph T. Costello and Alan E. Donnelly
Centre for Physical Activity and Health Research, Department of Physical Education and Sport Sciences, University of Limerick, Castletroy, Limerick, Ireland

https://doi.org/10.36866/pn.85.24

Whole body cryotherapy (WBC) is a cooling treatment that has recently gained widespread popularity amongst athletes, with a range of claims being made regarding its efficacy, particularly in aiding recovery from training. WBC involves repeatedly exposing an individual, dressed in minimal clothing, to extremely cold air (–100 to –130°C) for 2 to 4 minutes (Costello et al. 2011). During WBC, the individual experiences temperatures that are between 30–50°C colder than the lowest temperature ever recorded in Antarctica. Consequently, WBC is causing much debate amongst physiologists, physiotherapist, clinicians and sports people alike regarding its effectiveness and potential risks. This debate has intensified with the news that former 100 m Olympic Champion Justin Gatlin suffered frostbite after visiting one of these chambers (www.bbc. co.uk). The cause of this incident was most probably wet socks; the extreme cold can rapidly penetrate shoes through direct contact with the ground. Though the skin is exposed to the cold during WBC (many WBC participants just wear shorts), the relatively low thermal conductivity of air, lack of air movement and the short duration of exposure normally reduce the risk of cold injury. Most operators also ensure that the participants wear gloves and facemasks. WBC chambers were introduced from Japan to Europe in 1982 and the use of this treatment continues to rise despite the paucity of published literature in the area. International athletes, including rugby players, soccer players and track and field athletes, have reported using WBC as a method of recovery from sports training and competition. WBC is being promoted in sports medicine as a treatment for muscle injuries, syndromes of overuse and to enhance recovery between training sessions (Banfi et al. 2009). One specific claim that has been made is that WBC is effective in treating exercise-induced muscle soreness and damage. We have undertaken a study to evaluate WBC treatment effectiveness on indices of muscle function or soreness following an exercise bout specifically designed to induce a moderate level of temporary, repairable muscle damage.

The hypothesis of the current study was that WBC would be no more effective on muscle soreness recovery following eccentric exercise than a sham treatment (Costello et al. 2011). To address this hypothesis, we conducted a randomised controlled laboratory study in a two-group design (control and treatment). Despite the growing use of WBC, this was the first study of its kind to assess the effects of WBC treatment on recovery from muscle-damaging exercise. A group of 18 healthy and active participants with a mean age of 21.2 ± 2.1 years, who were blinded to the hypothesis of the study, performed an eccentric exercise bout consisting of 100 high-force maximal eccentric contractions of the left knee extensors on an isokinetic dynamometer (a device that measures muscle strength). These 18 volunteers were randomly assigned to either a WBC group (7 males and 2 females) or a control group (7 males and 2 females). Twenty-four hours later the participants received two bouts of either WBC or the control treatment 2 hours apart. The WBC treatment consisted of the subjects standing in a pre-cooling room at –60 ± 3°C for 20 seconds before entering and walking slowly around a second room at –110 ± 3°C for 3 minutes. In the control group, the subjects followed the same procedure as the WBC except both chambers were set at a temperature of 15 ± 3°C. Maximal voluntary isometric contraction force (MVIC) of the left knee extensors and subjects’ subjective assessment of muscle soreness was measured immediately before and after the exercise bout and at 48, 72 and 96 hours following eccentric exercise. MVIC (which was reduced by 40%) and the subjects’ subjective assessment of muscle soreness were both significantly affected in both groups, compared to baseline, following the eccentric exercise. Although no biopsies were collected in this study, the force loss recorded is indicative of underlying muscle damage. These outcome measures did not return to baseline for at least 96 hours following the exercise bout, and there were no differences between the WBC and the control group at any time-point during recovery. The results of this study suggest that two bouts of WBC were ineffective in improving recovery from eccentric exercise when administered 24 hours after eccentric exercise. However, it should be noted that recent studies suggest that WBC might have an anti-inflammatory effect (Banfi et al. 2009; Pournot et al. 2011).

Further research studies we have undertaken addressed the possible effects cryotherapy may have on proprioceptive acuity. We have previously systematically reviewed (Costello & Donnelly, 2010) and studied (Costello & Donnelly, 2011; Costello et al. 2011) the effects of cold on proprioception, in the form of joint position sense, and concluded that until further evidence is provided, clinicians and coaches should be cautious when returning individuals to tasks requiring components of proprioceptive input immediately after a cryotherapy treatment (Costello & Donnelly, 2010). Proprioceptive or positional sense deficits following cryotherapy could be attributed to a reduction in tissue temperatures, nerve conduction velocity, the eventual blocking of conduction and alterations in motor output. However, to date there has been little research in this area and it may warrant further investigation. The potential of cold-induced reductions in proprioception following WBC is especially important for elite athletes who have reported using WBC before or between sessions on the same day. In a sample of 36 healthy volunteers we found that force proprioception, joint position sense and MVIC of the knee extensors were unaffected following WBC exposure and that WBC does not increase the risk of proprioceptive-related injury (Costello et al. 2011). Consequently, individuals who choose to utilise this protocol of WBC before a training session or athletic participation do not appear to be at a higher risk of proprioceptive-related injury.

In summary, WBC is rapidly gaining popularity amongst athletes and sports people. To date there has been no convincing, unequivocal support for the therapy’s effectiveness in improving muscle functional recovery published in the peer-reviewed literature. Despite this, individuals continue to use WBC protocols that lack rigorous physiological assessment, and may perhaps be of limited value. Finally, WBC does not reduce proprioceptive acuity but chamber operators, clinicians and sports people need to be continuously vigilant of the potential of the technique to result in cold-induced injury.

References

Banfi G, Melegati G, Barassi A, Dogliotti G, Melzi d’Eril G, Dugue´ B & Corsi M (2009). Effects of whole-body cryotherapy on serum mediators of inflammation and serum muscle enzymes in athletes. J Therm Biol 34, 55–59.

Costello JT, Algar LA & Donnelly AE (2011). Effects of whole body cryotherapy (–110°C) on proprioception and muscle soreness. Scand J Med Sci Sports (epub- published online ahead of print).

Costello JT & Donnelly AE (2010). Cryotherapy and joint position sense in healthy participants: a systematic review. J Athl Training 45, 306–316.

Costello JT & Donnelly AE (2011). Effects of cold water immersion on knee joint position sense in healthy volunteers. J Sport Sci 29, 449–456.

Pournot H, Bieuzen F, Louis J, Fillard J, Barbiche E & Hausswirth C (2011). Time-course of changes in inflammatory response after whole-body cryotherapy multi exposures following severe exercise. PLoS ONE 6, e22748. http://news.bbc.co.uk/sport2/hi/athletics/14648191.stm accessed on the 04.10.2011.

Acknowledgements

We would like to acknowledge The Physiological Society who provided a Travel Grant to Joseph Costello to orally present these findings at the 2010 Main Physiological Society Meeting in Manchester.