Regular cold-water immersion may blunt strength gains but leaves endurance performance unchanged

Researchers conducted a systematic review and meta-analysis of controlled human trials examining what happens to athletic performance when cold-water immersion is used routinely alongside structured training programs. The pooled evidence suggested that habitual cold-water immersion was associated with meaningfully reduced strength and power adaptations from resistance training, while aerobic performance outcomes showed no meaningful difference compared with training alone.

What the study found

The central finding runs counter to how cold-water immersion is often promoted: when used consistently during resistance training programs, it was associated with worse outcomes across multiple strength measures — including maximal single-effort strength, sustained strength endurance, and explosive ballistic efforts — compared with training without regular immersion. The pooled effect sizes for these strength-related outcomes were moderate in magnitude and statistically robust.

For athletes focused on aerobic development, the picture was different. Across endurance-trained participants, habitual cold-water immersion showed no detectable association with changes in time-trial power output or maximal aerobic capacity. The effect sizes for these outcomes were essentially zero, with confidence intervals spanning both sides of no effect, suggesting the null result was not simply a matter of insufficient data.

The authors interpreted these divergent patterns as consistent with a hypothesis that cold-induced suppression of certain cellular signaling pathways may interfere with the molecular processes that drive muscle growth and force production, while leaving the separate pathways underlying aerobic adaptation comparatively unaffected. This mechanistic framing is speculative within the review itself and was not directly tested by the included studies.

Because the review pooled only eight articles, the estimates carry meaningful uncertainty, and the authors expressed appropriate caution about the strength of the conclusions — particularly for the endurance findings, where the absence of an effect could partly reflect limited statistical power.

Limits worth knowing

The meta-analysis was built on just eight controlled studies, which constrains both statistical power and the ability to explore variation across populations, training volumes, or immersion protocols. The literature search closed in late 2019, so subsequent research is not captured. Included participants were predominantly trained or recreationally active adults, so findings may not extend to novice exercisers or other groups. The review did not assess long-term health outcomes, injury rates, or subjective recovery experience. No funding disclosures were identified in the abstract, and potential conflicts of interest are not described there.

About this entry. The Heartwood Review summarizes published, peer-reviewed research in its own words and links to the original source. It is not medical advice; consult a physician before beginning or changing any thermal or recovery practice. Findings summarized here describe the study cited, not any product sold by Teak & Marble Atelier. Corrections.