The effects of cold water immersion after rugby training on muscle power and biochemical markers

During rugby game, or intensive rugby training there are many high intensity explosive exercises and eccentric muscle contractions, therefore adequate recovery is very important to rugby players. In the present study we have tested the effects of cold water immersion (CWI) after game-simulated (80 min.) rugby training on muscle power recovery and blood markers of muscle damage. Twenty well-trained collegiate male rugby players (age: 20.3 ± 0.6 years old, body height: 1.74 ± 0.05 m, body weight: 85.4 ± 2.0 kg, body fat: 18.2 ± 1.4 %) volunteered for this study. This study was conducted as a cross-over design; i.e., the subjects were randomly assigned either to CWI (n = 10) or passive rest condition (n = 10) for the 1^st trial and 1 week later the subjects were switched conditions for the 2^nd trial. After the simulated rugby training, including tackles and body contacts, muscle functional ability and blood markers of muscle damage were tested immediately, after CWI or passive rest, and again 24 hours later. Statistical analysis of all muscle functional tests (10 m dash, counter movement jump, reaction time, side steps) except for 10 seconds maximal pedaling power and blood makers of muscle damage (aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and creatinine) revealed significant main effects for time (p < 0.05). However, no statistically significant interactions were found in any of the muscle functional tests and blood markers between groups and time courses. Our results suggest that a rugby game induces muscle damage and reduces muscle function. However, CWI has no significant restorative effect after an 80-minute rugby game in terms of muscle damage.