Effect of moderate and cold-water immersion on strength and muscular weight changes following resistance training in Rats

Nowadays, cold-water immersion (CWI) has been established as a promising means to support recovery in high performance sports after highly intensive training bouts or competitions. There are many studies about effectiveness of acute CWI to support recovery after strenuous exercise, but the overall results seem to be conflicting. However, adaptational aspect has been widely neglected. Therefore, we analyzed the effects of immersion in cold and moderate water after resistance training on the some adaptations of strength training. In all, 32 male Sprague-Dawley rats (8-weeks) were assigned randomly into 4 equal groups including control (208.50±22.50 g), resistance training (208.87±26.70 g), resistance training + moderate water immersion (208.37±16.30 g.) and resistance training + cold water immersion (218.75±33.20 g) groups. The resistance training consisted of climbing (5 reps/3 sets) a ladder (120 cm) carrying load (equal to a percent of body weight) suspended from the tail. At last set (during 6 minute), rats in immersion water groups, immersed within container consisted water with 27˚C and 14˚C respectively. This process repeated 3 times a day during 8 weeks. At the first and last session, ladder climbing strength maximal was measured. Immediately after euthanasia (24 h after final training session), the flexor hallucis longus (FHL) and soleus muscles and subcutaneous-inguinal fat tissue was exposed and weighed. The data was analyzed with the one-way ANOWA method and significance level considered if p Results showed that subcutaneous-inguinal fat (p=0.01), FHL and soleus weight (p=0.01) and maximal strength of ladder climbing (p=0.001) were significantly different in all studied group; so the best improvement was obvious at the resistance + moderate water immersion group. It is concluded that immersion in moderate water have a better impact on the strength training adaptations in rats.