Cold-water immersion shows mixed effects on post-exercise muscle strength recovery

For countermovement jump (CMJ), a test of explosive power, CWI produced a transient impairment immediately post-exercise (g = −0.68 at 0 hours), but this deficit disappeared by 24–48 hours, suggesting a time-dependent pattern. Regarding muscle soreness on visual analog scales, CWI was linked to lower overall pain scores (g = −0.58, 95% CI [−0.99 to −0.16]), though the evidence was very low certainty and heterogeneity was substantial. For creatine kinase (CK), a biochemical marker of muscle damage, a small pooled reduction appeared (g = −0.43), but this effect largely disappeared after statistical adjustment for publication bias. The authors emphasize that certainty of evidence was compromised by publication bias, high heterogeneity, and sensitivity analyses that weakened key findings, particularly for CK and soreness measures.

The meta-analysis detected a critical time-dependent effect on explosive power: CWI produced a pronounced transient impairment at 0 hours (−0.68 effect size) that fully resolved by 24–48 hours. This suggests cold immersion may acutely suppress neuromuscular power output, a consideration if another power-dependent task is planned soon after. The soreness benefit (−0.58 effect size) was modest and not robust; cluster-robust sensitivity analyses and adjustment for publication bias substantially weakened this finding, suggesting selective reporting of positive results across studies. The CK signal also did not survive adjustment for bias (effect reduced from −0.43 to −0.16). Across all outcomes, heterogeneity was high, indicating substantial variability in study populations, protocols, immersion temperatures, durations, and timing—factors that likely explain why some trials found benefit and others did not. The authors note that CWI may be most useful for short-term symptom management and next-day recovery readiness when pain reduction is the priority, but is not a replacement for strength-building adaptation.