Acute cold-water immersion reduces subjective soreness but transiently impairs immediate explosive powerCold water immersion may reduce muscle soreness after exercise

OBJECTIVE: This study aimed to investigate the time-dependent effects of a single bout of acute cold-water immersion (CWI) on the recovery of post-exercise maximal muscle strength, explosive power, biochemical markers of muscle damage, and subjective pain, with the specific goal of determining the optimal temporal window for its practical application. METHODS: A systematic search was conducted in PubMed, Web of Science, Cochrane Library, and Embase databases for studies published from inception to September 1, 2025. Randomized controlled trials (RCTs) comparing a single bout of acute CWI with passive recovery regarding their effects on post-exercise strength recovery in healthy individuals were included. Methodological quality, risk of bias, and certainty of evidence were assessed using the Physiotherapy Evidence Database (PEDro) scale, the Risk of Bias 2 (RoB 2) tool, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, respectively. Statistical analysis was performed using Stata-MP 18.0 software. RESULTS: Twenty-two RCTs were included. For maximal voluntary isometric contraction (MVIC), no significant overall or time-dependent effects were observed (g = 0.08, 95% confidence interval (CI) [-0.11-0.26],  = 0.42; moderate certainty). For countermovement jump (CMJ) , the overall effect was not significant (g = 0.01, 95% CI [-0.25-0.28],  = 0.92), but a significant subgroup difference across time points was detected ( < 0.01; low certainty), with a transient impairment immediately post-exercise (0 h: g = -0.68, 95% CI [-1.16 to -0.20],  = 0.01) that was no longer evident by 24-48 h. For visual analog scale (VAS), CWI was associated with lower overall soreness scores (g = -0.58, 95% CI [-0.99 to -0.16],  = 0.01), although heterogeneity was substantial and certainty was very low. For creatine kinase (CK), the initial pooled effect suggested a small reduction (g = -0.43, 95% CI [-0.67 to -0.19],  < 0.01; low certainty), but this effect was attenuated to non-significance after trim-and-fill adjustment (g = -0.16, 95% CI [-0.44-0.12]). Cluster-robust sensitivity analyses preserved the direction of CK and VAS effects but attenuated their statistical significance. CONCLUSION: Acute CWI exerts outcome-specific effects on post-exercise recovery. It showed no meaningful effect on MVIC, transiently impaired immediate explosive performance, and may reduce subjective soreness, whereas the apparent CK benefit was not robust after adjustment for publication bias. The CK and VAS findings should be interpreted cautiously because heterogeneity, publication bias, and dependency-adjusted sensitivity analyses weakened the certainty of inference. Acute CWI may be most relevant when short-term symptom control and next-day recovery readiness are prioritized, but its timing should be considered carefully when another power-dependent task is scheduled soon after exercise.