Cryotherapy

Whole-body chambers and rheumatic disease

Reviews attribute whole-body cryotherapy to the Japanese physician Toshiro Yamauchi. A 2017 review states that it entered clinical practice 'forty years ago' after his observation that cold combined with exercise appeared beneficial for patients with rheumatoid arthritis after winter mountain holidays. A 2010 review describes the therapy as proposed 30 years earlier for rheumatic diseases, and a 2023 scoping review states that he designed the first cryosauna in 1979.

The dates therefore differ by source and are approximate. None of the sources opened for this page gives 1978, and none cites a primary publication by Yamauchi. The 2023 scoping review adds that cryogenic chambers were developed in Europe shortly after the turn of the 1980s and spread to Poland and Germany, where they were integrated into healthcare systems.

Cold water and local cold in sport

A 2021 position paper notes that cold exposure, locally or of the whole body, has been used for a long time in sport and medicine. A Cochrane review reports that cold-water immersion in water below 15 degrees C is one of the most popular strategies used after exercise, and a 2014 review observes that local ice packs and immersion are less expensive forms of cryotherapy than chambers. The sources reviewed do not trace the history of cold-water immersion before its modern sports use.

Whole-body cryotherapy and cryostimulation

A 2021 position paper from an International Institute of Refrigeration working group defines whole-body cryotherapy (WBC) as extreme cold therapy or stimulation in which a person stands in a cold room for 1 to 4 minutes, with felt air temperatures ranging from minus 60 to minus 195 degrees C. The same paper uses cryostimulation alongside cryotherapy, and a 2023 scoping review describes true WBC as exposing the entire body, including the head, to very cold dry air in refrigerated chambers.

Partial-body cryotherapy and cryosaunas

Partial-body cryotherapy (PBC) places the body in a cabin with the head outside. The 2023 scoping review states that PBC uses direct injection of liquid nitrogen mist, imposes cold and hypoxia together, and is often mistaken for WBC. It argues that some safety reports used to question WBC actually involved PBC. The 2021 paper adds that manufacturer-stated cryosauna temperatures of minus 110 to minus 195 degrees C correspond to measured air temperatures of roughly minus 10 to minus 42 degrees C.

Cold-water immersion and cryosurgery

Cold-water immersion, as defined in a Cochrane review, uses water temperatures below 15 degrees C. Cryosurgery is a different, clinical procedure in which clinicians freeze and destroy abnormal tissue. A 2021 dermatology guideline on actinic keratosis, for example, makes a strong recommendation for cryosurgery among lesion treatments. That guideline concerns a medical procedure for skin lesions and does not bear on wellness chambers or immersion.

Chamber sessions

A 2017 review describes a typical electric or nitrogen-cooled WBC session: the client passes through a vestibule at about minus 60 degrees C for roughly 30 seconds, then spends no more than 3 minutes in the main chamber at minus 110 to minus 140 degrees C. Clothing is minimal, with a bathing suit, socks, clogs, headband and surgical mask, and access is described as permitted only with skilled personnel present.

The 2021 position paper gives a range of 1 to 4 minutes, with a 1-minute first exposure commonly used for newcomers. It describes protection for the feet, hands and ears, a small surgical mask for the airways, and post-exercise recovery protocols of 1 to 5 sessions, at least two of them within 24 hours.

How the cold is produced

The 2021 paper distinguishes cold produced by mechanical refrigeration, using vapor compression cycles or cryogenic fluids, from cold produced mainly by liquid nitrogen. It lists static chambers claimed at minus 60 to minus 160 degrees C and forced-convection chambers at minus 40 to minus 60 degrees C, and notes that actual temperatures are often not shown in the literature. The 2017 review adds that free nitrogen vapors are heavy and tend to remain in a cabin.

Cold-water immersion protocols

In the Cochrane review of immersion after exercise, the water temperature, duration and frequency of immersion varied between the 17 included trials, as did the exercise and the setting. No single standard protocol is therefore described by the sources reviewed, and the review defined cold-water immersion only by the below-15 degrees C threshold.

Rheumatic and pain conditions

A 2010 review reports that WBC is used to relieve pain and inflammatory symptoms in many disorders, especially rheumatic conditions, and states that it is recommended for arthritis, fibromyalgia and ankylosing spondylitis. These are statements by the review authors about use, not tested findings. The Cochrane review discussed below examined only muscle soreness after exercise in healthy adults.

Sport recovery and mood

The 2021 position paper reports that WBC is promoted for post-exercise recovery, for reducing delayed-onset muscle soreness and for limiting inflammation. The 2021 position paper notes that athletes' testimony is generally positive but could reflect a placebo effect, and calls the supporting evidence limited and contradictory. A 2021 meta-analysis examined WBC as an add-on for mental health problems, particularly depressive symptoms.

Cochrane review of whole-body cryotherapy

The 2015 Cochrane review of WBC for exercise-related muscle soreness included four laboratory randomized trials with 64 physically active, predominantly young men. The trials differed in temperature, duration and frequency, all had a high risk of bias, and the evidence was graded very low quality. Compared with rest, self-reported soreness was lower at 1 hour (standardized mean difference minus 0.77, 95% CI minus 1.42 to minus 0.12; 20 participants), but the intervals at 24, 48 and 72 hours included no difference. The authors concluded that evidence was insufficient and noted none of the trials actively monitored adverse events.

Cochrane review of cold-water immersion

The 2012 Cochrane review of cold-water immersion included 17 small trials with 366 participants and rated study quality as low. Against rest or no intervention, pooled soreness scores favored immersion at 24 hours (standardized mean difference minus 0.55, 95% CI minus 0.84 to minus 0.27; 10 trials) and at 48, 72 and 96 hours, although results were heterogeneous. No differences were found against contrast or warm-water immersion. The authors concluded there was some evidence of reduced delayed-onset soreness compared with passive interventions, and that most trials did not monitor adverse events.

Other reviews of chambers

A 2014 review of ten controlled reports found weak evidence for effects on antioxidant capacity and inflammatory pathways, small randomized studies suggesting better subjective recovery and soreness but little functional benefit, and no adverse events, though predefined events were not actively tracked. It suggested that cheaper options such as ice packs or immersion offer comparable effects.

The 2021 mental health meta-analysis included ten studies, six of them controlled, with 294 participants receiving WBC. The pooled within-group effect was large (Hedges' g 1.63, 95% CI 1.05 to 2.21) with very high heterogeneity (I-squared 93%), while the between-group effect was medium (g 0.76, 95% CI 0.17 to 1.36). The authors called the evidence preliminary and the studies limited by bias, and they framed WBC only as an add-on to other care.

Effects on training adaptations

A 2021 narrative review reports that repeated post-exercise cold-water immersion may attenuate gains in maximal strength, power and muscle size from resistance training, without negatively affecting endurance adaptations. The authors describe the evidence on mechanisms as limited and the studies as methodologically varied. The 2021 chamber position paper makes a similar statement for regular cooling.

Reported adverse events

A 2023 scoping review of true WBC found five case reports and two randomized trials describing 16 adverse events. Minor events included headaches, dizziness or discomfort, reactive hypertension, lasting shivering, cold panniculitis and urticaria. Serious events included transient global amnesia, intracerebral hemorrhage, moyamoya syndrome and abdominal aortic dissection. The authors, who include WBC researchers, concluded that risks are within acceptable limits when contraindications and guidelines are followed. The 2021 position paper names cold burns and cold urticaria as the most common adverse events.

Nitrogen cabins, asphyxia and cold burns

The 2023 review states that cryosaunas carry inherent risks of cold burns and anoxia from direct injection of vaporized nitrogen, and cites a cold burn in a 71-year-old man whose back was burned by liquid nitrogen in a cryosauna. A 2017 review likewise warns that free nitrogen vapor in a cabin could present a risk of asphyxia, and the 2021 paper lists asphyxia as a potential risk. Recommended precautions include a viewing window or camera, protective equipment and a quick-exit door.

Contraindications and care boundaries

The 2017 review lists contraindications including Raynaud disease, cold intolerance, cryoglobulinaemia, cardiovascular disease, acute respiratory disorders, skin lesions, neuropathies and claustrophobia. The 2021 paper names unstable angina and New York Heart Association stage III and IV heart failure, and the 2023 review proposes adding migraine. The Cochrane reviews note that trials rarely monitored adverse events, and that extreme temperature is a potential hazard. Cryotherapy is not a substitute for assessment or treatment of pain, arthritis or mental health conditions, and evidence from clinical cryosurgery does not transfer to wellness use.