Effects of cold-water immersion after rugby-specific training on endurance performance

This study investigated whether whole-body cold-water immersion (CWI) following rugby-specific training influences endurance exercise performance 24 h later.

Eleven healthy male collegiate rugby players completed an incremental cycling test to determine peak oxygen uptake (V̇O2peak) and time to exhaustion at baseline (Pre). One week later, participants performed a standardized rugby-specific training session consisting of warm-up, skill-based passing, contact drills, individual training (i.e., conversion kicking and scrummaging), and a bronco endurance test (total duration: 180 min), followed by one of two recovery interventions in a randomized order: 1) whole-body CWI for 8 min at 15 °C (CWI) or 2) seated rest for 8 min (Control). Participants then performed the incremental cycling test 24 h after each intervention.

Training load during the rugby-specific training, assessed using heart rate-based training load and blood lactate concentrations, did not differ between the trials. Time to exhaustion (485±72 vs. 518±77 s, P=0.107, d=0.45) and V̇O2peak did not differ between the Control and CWI trials, whereas the relative changes in these variables from Pre were greater in the CWI than in the Control trials (both P<0.05). Oxygen uptake, minute ventilation, and rating of perceived exertion during submaximal exercise were similar across the Pre, Control, and CWI trials.

These results suggest that whole-body CWI following rugby-specific training may be associated with favorable changes in endurance exercise performance 24 h post-intervention compared with the control condition. However, the expectancy/placebo effect of water immersion on exercise performance could not be excluded.