Ice Baths Reconsidered: Landmark Review Maps When Cold-Water Immersion Helps Athletes and When It Backfires

Cold-water immersion has become one of the most recognisable rituals in modern sport, with athletes from elite soccer squads to weekend marathoners lowering themselves into icy tubs in pursuit of faster recovery. Yet the scientific picture has long been fragmented, with dozens of individual meta-analyses reaching seemingly conflicting conclusions about whether the practice actually works. Now, a comprehensive umbrella review published in Sports Medicine – Open has synthesised fifteen systematic reviews with meta-analyses, covering 161 unique primary studies and more than 3,200 participants, to deliver the most complete assessment to date of when post-exercise cold-water immersion genuinely aids recovery and when it may quietly undermine an athlete’s long-term goals.

The research team, led by Erfan Berjisian of Edith Cowan University and colleagues from institutions in Australia, the United Arab Emirates and beyond, followed Joanna Briggs Institute guidelines and searched eight databases, including Web of Science, Scopus, SPORTDiscus, CINAHL, the Cochrane Library, Embase, MEDLINE and PubMed. Methodological quality was appraised with the AMSTAR 2 checklist, and the certainty of evidence was graded using the GRADE framework. The review was prospectively registered with PROSPERO, and the authors calculated the degree of overlap between the included reviews using the corrected covered area formula, which came out at 10.4 percent, indicating moderate overlap overall, although the reviews examining strength and hypertrophy adaptations shared a striking 64 percent of their primary studies.

The headline finding is that cold-water immersion is neither a universal elixir nor a useless fad; its effects are sharply dependent on the outcome being measured and the timing of the next performance demand. For muscular strength recovery, the evidence was consistently underwhelming. Across four meta-analyses, immersion produced no significant improvement in maximal strength compared with passive rest or alternative recovery modalities at any timepoint up to 168 hours after exercise, with standardised mean differences hovering near zero. Athletes hoping that a cold plunge will restore their deadlift or squat strength faster appear to be hoping in vain.

By contrast, explosive and power-based performance told a far more interesting, time-dependent story. Jump performance was actually impaired in the first hours after immersion, with one meta-analysis reporting a large and significant drop in jump height of 2.71 centimetres when tested immediately after cooling, a finding consistent with well-established physics: colder muscle contracts more slowly and produces less power. But the picture reversed dramatically with time. The same review found a large improvement of 4.77 centimetres at 24 hours, and other analyses confirmed small-to-large gains in jump performance between 24 and 96 hours. Muscular power followed a similar pattern, improving significantly at 24 to 72 hours after both eccentric and high-intensity exercise, with pooled effect sizes reaching 0.65 in some analyses.

Endurance performance showed yet another temporal signature. A meta-analysis of fourteen studies found a significant improvement in endurance performance when testing occurred within roughly one hour of immersion, with a standardised mean difference of 0.50, but the benefit vanished at six, 24 and 48 hours. This pattern makes physiological sense: cold-water immersion rapidly lowers tissue temperature and cardiovascular strain, which is precisely what a fatigued athlete needs before a second bout in hot conditions or during tournament play with matches on consecutive days. Beyond that acute window, however, the review found no support for cold-water immersion as a strategy to blunt cumulative endurance fatigue across multiple days of training or competition.

Perhaps the most consequential finding concerns chronic adaptation. When cold-water immersion was applied repeatedly after resistance training over several weeks, it attenuated gains in one-repetition maximum, maximal isometric strength, strength endurance and ballistic performance, with effect sizes ranging from negative 0.50 to negative 0.73 in one meta-analysis. A Bayesian meta-analysis concluded that regular post-exercise immersion likely reduces resistance training-induced hypertrophy, albeit modestly, with a corrected standardised mean difference of negative 0.22. Intriguingly, the mode of immersion mattered: subgroup analyses showed that immersing only the exercised limbs significantly blunted strength gains, whereas whole-body immersion showed no meaningful detrimental effect compared with control. Endurance adaptations, meanwhile, appeared largely unaffected, with trivial pooled effects on time-trial performance and maximal aerobic power.

The mechanistic explanation for these blunted gains lies in molecular biology rather than in the tub itself. Experimental work has shown that cold-water immersion after resistance exercise dampens anabolic signalling, reduces ribosome biogenesis and satellite cell activity, and directly impairs muscle protein synthesis rates. Cooling, in effect, suppresses the very inflammatory and signalling processes that drive muscle to grow stronger and larger after heavy training. For athletes in a strength- or hypertrophy-focused training block, the practical implication is stark: the ice bath should be kept well away from the key lifting sessions, even if it is deployed strategically after technical or aerobic work elsewhere in the week.

Not every effect was negative or neutral. Cold-water immersion consistently reduced muscle soreness from one hour up to 96 hours after exercise, with small-to-moderate effects that were largest following high-intensity exercise. It also lowered circulating creatine kinase, a marker of muscle damage, significantly between 24 and 72 hours post-exercise, with pooled effects reaching negative 1.30, although no effect was seen in the first six hours or at 96 hours. Inflammatory markers told a different story: C-reactive protein and interleukin-6 were essentially unchanged up to 72 hours, suggesting that the soreness and damage-marker benefits do not require broad suppression of systemic inflammation. On the autonomic front, a single meta-analysis of fifteen studies reported a moderate-to-large improvement in vagally mediated heart rate variability, indicating faster parasympathetic reactivation, with colder water around 9 to 15 degrees Celsius outperforming thermoneutral immersion at 28 to 35 degrees.

The review also offered practical dosing guidance. Immersions of 10 to 15 minutes at water temperatures of 10 to 15 degrees Celsius appeared most effective for reducing muscle soreness, while 10 to 15 minutes at 5 to 10 degrees Celsius had the highest probability of being optimal for lowering creatine kinase and improving jump performance at 24 to 48 hours. Intermittent and continuous protocols performed similarly, and longer immersions of 16 to 20 minutes were not consistently beneficial, with experimental work cautioning that prolonged or aggressive cooling may impair glycogen restoration and delay recovery from muscle damage.

The authors are candid about the limitations of the evidence base. All fifteen included reviews were rated as low or critically low methodological quality, and most outcomes carried low to very low certainty of evidence, driven mainly by inconsistency, imprecision and the near-impossibility of blinding participants to frigid water. Roughly 90 percent of participants were male, leaving sex-specific responses to cold exposure largely unexplored. Still, the overarching message is clear and actionable: cold-water immersion should be periodised and individualised rather than applied routinely after every session. It is most defensible when recovery time is short, thermal strain is high, and the next bout is imminent, and it should be avoided immediately before explosive performance and during phases where strength and muscle growth are the priority. The ice bath, it turns out, is a precision tool, not a daily ritual.

Subject of Research: Effects of post-exercise cold-water immersion on athletic performance recovery and training adaptation

Article Title: Strategic Application of Post-exercise Cold-Water Immersion to Enhance Performance Recovery and Adaptation: An Umbrella Review of 15 Published Systematic Reviews with Meta-analysis

Article References: Berjisian, E., Miraftabi, H., Ihsan, M., Homer, K. A., Kendall, K., Roberts, L., & Abbiss, C. (2026). Strategic Application of Post-exercise Cold-Water Immersion to Enhance Performance Recovery and Adaptation: An Umbrella Review of 15 Published Systematic Reviews with Meta-analysis. Sports Medicine – Open, 12(1), Article 145. https://doi.org/10.1186/s40798-026-01116-8

Image Credits: AI Generated

DOI: 10.1186/s40798-026-01116-8

Keywords: cold-water immersion, exercise recovery, athletic performance, muscle soreness, creatine kinase, strength training, hypertrophy, endurance performance, heart rate variability, meta-analysis, sports medicine, recovery protocols