Cool water immersion after downhill running suppresses exercise-induced muscle damage in the rat soleus muscle

Abstract

[Purpose] Cryotherapy has been used to treat acute skeletal muscle damage, but there are some controversies about the effects of cryotherapy on exercise-induced muscle damage. In present study, we investigated the effect of cool water immersion on exercise-induced muscle damage. [Methods] Twelve-week-old male Wistar rats were divided into a control (Cont) group, exercise (Ex) group, and cool water immersion after exercise (Ex+W) group. Rats in the Ex and Ex+W groups performed downhill running at 16 m/min on a -16 degree incline, for 90 minutes. The rats of the Ex+W group were immersed in cool water (20 degrees C for 30 minutes) immediately after exercise. The soleus muscles were removed at 24, 48, and 72 hours after exercise, cross-sectional areas of muscle were stained with hematoxylin-eosin, and glucose-6-phoshate dehydrogenase (G6PD) activity was measured. [Results] Muscle damage was observed in both the Ex and Ex+W groups. The percentage of damaged muscle fibers in the Ex+W group was lower than that in the Ex group at 72 h. G6PD activity in the Ex+W group was lower than that in the Ex group at 48 and 72 h. [Conclusion] These results suggest that cool water immersion after downhill running suppresses exercise-induced muscle damage.