Recovery following Rugby Union matches: effects of cold water immersion on markers of fatigue and damage

Abstract

We investigated the effect of postmatch cold-water immersion (CWI) on markers of muscle damage, neuromuscular fatigue, and perceptual responses within 72 h after a rugby match. Twenty-two professional male rugby players were randomized into CWI (10 °C/10 min; <i>n</i> = 11) or control (CON: 30 min seated; <i>n</i> = 11) groups. Activity profile from Global Positioning Satellite systems and postmatch rating of perceived exertion were measured to determined match load. Biochemical (tumor necrosis factor alpha (TNF-α), interleukin-6), neuromuscular performance (squat (SJ) and countermovement jumps (CMJ), peak power output (PPO), rate of force development (RFD), stiffness, 10- and 30-m sprint time, and perceptual markers (soreness, perceived recovery) were obtained before and immediately after the match, and then at 30 min, 24 h, 48 h, and 72 h after the match. Magnitude-based inference and Cohen's effect size (ES) were used to analyze change over time and between groups. Thus, the higher/beneficial, similar/trivial, or lower/harmful differences were evaluated as follows: <1%, <i>almost certainly not</i>; 1% to 5%, <i>very unlikely</i>; 5% to 25%, <i>unlikely</i>; 25% to 75%, <i>possible</i>; 75% to 95%, <i>likely</i>; 95% to 99%, <i>very likely</i>; >99%, almost certainly. Changes were <i>unclear</i> for the match loads, sprint times, and perceptual markers between groups. Higher %ΔSJ at 24 h (<i>very likely</i> (ES = 0.75)) and in %ΔPPO_SJ at 48 h (<i>likely</i> (ES = 0.51)) were observed in CWI than in CON. Values in %ΔRDF_CMJ were higher immediately after (<i>likely</i> (ES = 0.83)), 30 min after (<i>very likely</i> (ES = 0.97)), and 24 h after the match (<i>likely</i> (ES = 0.93)) in CWI than in CON. Furthermore, %Δlog TNF-α were lower in the CWI group than in the CON group immediately after (<i>almost certainly</i> (ES = -0.76)), 24 h after (<i>very likely</i> (ES = -1.09)), and 72 h after the match (<i>likely</i> (ES = -0.51)), and in Δstiffness_SJ at 30 min after (<i>likely</i> (ES = -0.67)) and 48 h after the match (<i>very likely</i> (ES = -0.97)). Also, different within-groups effects throughout postmatch were reported. Implementing postmatch CWI-based strategies improved the recovery of markers of inflammation and fatigue in rugby players, despite no change in markers of speed or perceptual recovery.