Effects of contrast water therapy on fatigue recovery in athletes: systematic review and three-level meta-analysis

Background High-intensity training and competition often lead to severe fatigue in athletes, making effective recovery interventions essential. This three-level meta-analyses aimed to systematically evaluate contrast water therapy (CWT) and passive recovery (PAS), and explore which intervention is more effective for fatigue recovery. Methods Following PRISMA guidelines, a systematic search was conducted in PubMed, Web of Science, Cochrane Library, Embase, and Scopus on August 23, 2026. Pooled effect sizes were estimated using a three-level random-effects meta-analysis, and a variance–covariance matrix was constructed by specifying the correlation between effect sizes within the same study (ρ = 0.5) to account for the dependence arising from multiple outcomes and multiple time points within a study. Accordingly, three-level models were further fitted separately for the three outcomes: VAS 0–10, CK, and Borg 1–10. Risk of bias was assessed using the Risk of Bias 2.0 tool, and the certainty of evidence was evaluated using the GRADE framework. Results A total of 10 studies involving 199 athletes (age: 15.5 ± 1.0 to 26.2 ± 5.8) were included. Both variance components of the three-level model were supported (between-study σ² 3 = 0.553; within-study σ² 2 = 0.154; likelihood ratio test P < 0.0001). Contrast water therapy significantly reduced perceived exertion (Borg 1–10: 5 studies, 10 effect sizes; Hedges’ g = −1.009, 95% CI: −1.672 to −0.346; P = 0.007; I ² = 70.41%; low certainty) but had no statistically significant effect on muscle soreness (VAS 0–10: 5 studies, 12 effect sizes; g = −0.439, 95% CI: −1.619 to 0.741; P = 0.431; I ² = 93.85%; very low certainty) or on CK (3 studies, 6 effect sizes; g = −0.257, 95% CI: −0.614 to 0.100; P = 0.123; I ² = 0%; low certainty). Conclusion Contrast water therapy may improve perceived recovery, specifically perceived exertion. Although the primary analysis suggests a possible benefit of CWT on perceived exertion, the available evidence remains insufficient to draw strong conclusions about the reliability or practical magnitude of this effect. For perceived muscle soreness and circulating CK, no statistically significant effect was detected, but given the limited evidence, these findings do not permit a conclusion of equivalence with passive recovery. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/login , identifier CRD420251075430.