A Cochrane review of four small laboratory trials (64 physically active, predominantly young male adults) found insufficient, very low quality evidence that whole-body cryotherapy reduces self-reported muscle soreness or improves subjective recovery compared with rest. Confidence intervals at 24, 48 and 72 hours included no difference, and no trial actively monitored adverse events.
What it shows: Cochrane review of only four laboratory trials covering 64 physically active young adults, all but four of them male, mean age 23; every trial had design features carrying a high risk of bias and all outcomes were graded very low quality, with no data at all in women or elite athletes.Meta-analysis · Cochrane Database Syst Rev