Contrast water therapy cleared lactate and reduced fatigue in swimmers but did not lift performance

A crossover study put fifteen collegiate male swimmers through two identical high-intensity interval sessions, then assigned each swimmer to either contrast water therapy or passive rest after one session and the opposite condition after the other. Contrast water therapy was associated with meaningfully lower blood lactate and reduced self-reported fatigue compared with passive rest, yet neither blood pressure nor 100-metre swim times differed between conditions.

What the study found

The study found no advantage for contrast water therapy over passive rest on the outcome most athletes care about most: actual swimming performance. Times for a 100-metre effort recorded after the recovery period were statistically indistinguishable between the two conditions, a null result the authors report straightforwardly.

On physiological markers, blood lactate measured after the recovery window was notably lower following contrast water therapy than after passive rest, a difference that reached statistical significance. The authors interpret this as evidence that the alternating hot-and-cold immersions may accelerate the body's clearance of metabolic byproducts, though the crossover design cannot establish a direct causal mechanism.

Perceived fatigue, rated on a visual analogue scale, was also lower after contrast water therapy, suggesting swimmers felt more recovered even when their measurable performance had not improved. The authors note that this perceptual benefit could itself be meaningful in training contexts where athletes must complete multiple sessions in a day or across consecutive days.

Individual responses varied considerably. While most participants showed improved lactate clearance and lower fatigue scores with contrast water therapy, performance responses were mixed across the group. The authors flag this heterogeneity as a reason to be cautious about applying group-level averages to any individual swimmer.

Limits worth knowing

The sample was small at fifteen participants, all collegiate males in a narrow age range, which limits how broadly the findings can be applied to female athletes, masters swimmers, or other competitive populations. The study was conducted at a single site and covered only immediate post-session recovery, so nothing can be said about effects on training adaptation over weeks or months. The crossover design helps control for individual differences but cannot eliminate the possibility that session order or fatigue accumulation influenced results. Funding sources are not disclosed in the available abstract. The specific immersion temperatures and timing used here may not reflect conditions available in all training environments, and no psychological or hormonal markers beyond lactate and blood pressure were captured.

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.