Effect of cold water immersion performed on successive days on physical performance, muscle damage, and inflammatory, hormonal, and oxidative stress markers in volleyball players
The aim of this study was to investigate the effects of daily cold water immersion (CWI) on physical performance, muscle damage, and inflammatory, hormonal, and oxidative stress markers in volleyball. Six players were submitted to CWI and six players to a placebo, during 5 training days. Thigh circumference, squat jump, and agility were measured on the 1st, 3rd and 6th days. On the 1st and 6th days, blood and saliva were collected for analysis of oxidative stress, muscle damage, and inflammatory and hormonal levels. Muscle soreness and countermovement jump were quantified daily. The physical performance comparisons did not present differences and the only between group comparison with a large effect size (ES = -1.39) was in Δ% between day 1 and day 2 for CMJ. DOMS and creatine kinase increased in both groups and the ES of between group comparisons of Δ% between moments were not more than moderate. Thigh circumference increased only in the placebo group (P = 0.04) and the ES of the between group comparisons of Δ% between moments was large (1.53). No differences were found in oxidative stress, or inflammatory markers. Cortisol decreased only in the CWI-group (P < 0.05) and the ES of the between group comparisons of Δ% between moments of the testosterone/cortisol ratio (- 1.94) and IGF-1 (- 1.34) were large. Despite the positive effects of daily CWI on muscle edema and hormonal status, the limited effects of CWI on performance, muscle damage, inflammation markers, and ROS mediators signal the unimportance of the daily practice of this recovery method in volleyball players.