The use of various temperature protocols (cryotherapy, cold water immersion/ice baths, contrast therapy) for increased recovery and performance has garnered mainstream acceptance from athletes.
Here, we review the literature to examine the effectiveness of these treatment methodologies, as well as methods of best practice.
Summary:
- Cryotherapy methods result primarily in subjective (self reported) improvements, not objective (measures of physiological change) changes.
- Cold water immersion showed superior subjective results to ‘cold air’ cryotherapy chambers.
- Research has found that a placebo water immersion is as effective as actual cold water immersion in self reported (subjective) measures.
The primary treatment methodologies commonly used are:
- Cold water immersion: Immersing the entire body in an ice-bath (or similar) for various periods of time.
- Whole body cryotherapy (WBC): “…exposure to very cold air that is maintained at -110 degrees C to -140 degrees C in special temperature-controlled cryochambers, generally for 2 minutes.” (Banfi et. al., 2010).
- Cold air: Application of cold air to the body.
- Ice pack: Topical application of an ice pack/cold pack to isolated areas of the body.
The claims made by practitioners and users of these methods include:
- Reductions in recovery time from exercise.
- Increased performance.
- Reductions in joint pain.
- Reductions in inflammation.
- Modification of hormone levels.
- Improvements in immune function.
- Treatment of various chronic diseases.
- Improvements in mental health (including cognitive and mental disorders, as well as stress, depression and anxiety).
- Aesthetic benefits (including changes in hair, nails and skin).
In “The Effect of Post-Exercise Cryotherapy on Recovery Characteristics: A Systematic Review and Meta-Analysis”, Hohenauer et. al., “critically determine(d) the possible effects of different cooling applications, compared to non-cooling, passive post-exercise strategies, on recovery characteristics after various, exhaustive exercise protocols up to 96 hours.” They reviewed 36 articles on the topic.
To examine the above claims significant research has examined “…cryotherapy, as a post-exercise intervention… by means of subjective ratings of Delayed Onset Muscle Soreness and general ratings of perceived exertion (RPE), objective attenuations of blood plasma markers such as creatine-kinase (CK) and lactate-levels, or blood plasma cytokines encompassing Interleukines (IL) and C-reactive protein (CRP)” (Hohenauer et. al., 2015). Both subjective and objective ratings were made. The primary findings of these examinations were:
Subjective:
- “…cold therapy (CWI) significantly alleviated the symptoms of DOMS 24 hrs, 48 hrs and 96 hrs after the cooling application”.
- “Cold water immersion was the most used cooling application across the studies and showed the best effect between cold air, cold pack and whole body cryotherapy (WBC).”
- “…cooling significantly reduced the RPE (rate of perceived exertion of additional exercise) after 24 hrs of recovery.”
- In well trained subjects, researchers found “…results that favoured cooling compared to the control conditions. This was true for DOMS 24 hrs and 48 hrs and RPE 24 hrs and 48 hrs”.
Objective:
- “Cooling did not affect objective recovery variables such as lactate-levels, CK-levels or IL6-levels. However, significant differences could be observed favouring cooling at CRP 48 hrs.” The researchers went on to say that C Reactive protein (an inflammation marker) was the only measure that had a favourable result, and that that result only occurred at 48 hours, and only in a small group of studies, “…which made this result questionable.”.
Conclusions from the research:
- “Whole body cooling and cold air applications probably do not cool as deep as cold applications with direct contact to the skin, but only affect skin temperature.”
- “…cryotherapy techniques used in humans do not sufficiently cool muscle tissue to produce any physiological effect.”
- “…cryotherapy or icing, as currently practiced, will not likely be successful in cooling human muscle sufficiently to have any significant influence on muscle repair regardless of the degree of injury.”
- “…an administered placebo immersion… is as effective as cold water immersion.” and “… the commonly hypothesized physiological benefits surrounding CWI are at least partly placebo related .” Broatch et. al., 2014.
Hohenauer et. al.’s review of the research concluded that “To sum up the results of the individual studies: the mean temperature of the studies, showing a significant result favouring cooling compared to the passive recovery intervention, was 10°C (range: 5°C to 13°C). The reported and suggested cooling time for alleviating the subjective symptoms is 13 min (range: 10 min to 24 min).” It must be noted though that the only significant benefits were subjective, and additional research showed the placebo effect to be as powerful as cold water immersion.
Further Reading: Ice, Ice, Maybe (from The CrossFit Journal): Some athletes and experts swear by ice baths, while others say they’re useless or even detrimental. Hilary Achauer investigates the potential end of the Ice Age.
References:
Banfi, G., Lombardi, G., Colombini, A., & Melegati, G. (2010). Whole-Body Cryotherapy in Athletes. Sports Medicine, 40(6), 509-517. doi:10.2165/11531940-000000000-00000
Broatch JR, Petersen A, Bishop DJ. Postexercise cold water immersion benefits are not greater than the placebo effect. Medicine and science in sports and exercise. 2014;46(11):2139–47. doi: 10.1249/MSS.0000000000000348 pmid:24674975.
Hohenauer, E., Taeymans, J., Baeyens, J., Clarys, P., & Clijsen, R. (2015). The Effect of Post-Exercise Cryotherapy on Recovery Characteristics: A Systematic Review and Meta-Analysis. PLOS ONE PLoS ONE, 10(9). doi:10.1371/journal.pone.0139028
