Temperature-dependent effects of post-exercise cold-water immersion on recovery: a systematic review and meta-analysis.

backgroundCold-water immersion (CWI) is widely used as a recovery intervention to facilitate post-exercise recovery; however, inconsistent conclusions remain regarding temperature-dependent effects. Therefore, this meta-analysis aimed to comprehensively examine the effects of CWI on post-exercise recovery, focusing on delayed onset muscle soreness (DOMS) and biochemical markers of muscle damage, including creatine kinase (CK) and myoglobin (Mb), and to quantitatively compare the effects across different water temperatures.

methodsThis study was conducted as a systematic review and meta-analysis in accordance with the PRISMA guidelines. Relevant studies were identified through searches of the PubMed, Web of Science, SPORTDiscus and SCOPUS databases. Only studies employing a single-session CWI intervention were included, and a total of 52 studies met the inclusion criteria. Effect sizes were calculated using standardized mean differences (SMD), and subgroup analyses were performed to compare the effects of water temperatures of approximately 5 °C, 10 °C, and 15 °C. The review protocol was not prospectively registered, and temperature subgroup analyses should be considered exploratory.

resultsThe meta-analysis demonstrated that CWI produced statistically significant moderate-to-large effects on DOMS, CK, and Mb during the post-exercise recovery period (DOMS: SMD = - 0.81; CK: SMD = - 0.64; Mb: SMD = - 0.93; all p < 0.001). Subgroup analyses by water temperature showed numerically smaller reductions in DOMS at ≈5 °C (SMD = - 0.2) compared with ≈10 °C (SMD = - 0.8) and ≈15 °C (SMD = - 0.9); however, the difference between temperature subgroups was not statistically significant (p = 0.79). CK and Mb were significantly reduced across all temperature ranges, with no significant differences between temperature subgroups.

conclusionOn average, CWI was associated with reductions in DOMS, CK, and Mb, although substantial heterogeneity and wide prediction intervals indicate that these effects may not be consistently reproduced across settings. Numerically larger reductions in DOMS were observed at approximately 10-15 °C than at ≈5 °C, but neither subgroup analysis nor meta-regression confirmed a temperature-dependent effect. No water-temperature range can currently be considered superior. CLINICAL TRIAL NUMBER: Not applicable. REVIEW REGISTRATION: Not prospectively registered.