Effects of eccentric exercise on different slopes.

OBJECTIVES: Eccentric contraction occurs when the muscle lengthens under tension. Damage-induced responses seen in the muscle after eccentric exercise usually experienced by sedentary individuals. This study aims to investigate muscle damage on different slopes. METHODS: 32 male Wistar albino rats randomly divided into four groups: sedentary, horizontal running, and eccentric exercise (-8 degrees , -16 degrees ) groups. Animals ran for 90 min with the speed of 25 m/s for five days. After 48h from the last exercise, rats were sacrificed, and plasma creatine kinase (CK), heat shock protein 70 (HSP70) levels were examined. Plasma and soleus total oxidant/antioxidant status (TOS-TAS) and histological changes of soleus muscle assessed. RESULTS: CK and HSP70 significantly increased in 16 degrees EE group. TOS increased at 16 degrees EE and 8 degrees EE, but oxidative stress index (OSI) was only high at 8 degrees EE group. Mononuclear cell infiltration and the angiogenesis increased in soleus after eccentric exercise, and there was a correlation with slope. Sarcomere breaks were detected in 16 degrees EE group also in a correlation with slope. CONCLUSIONS: Consequently, sedentary individuals are vulnerable to injuries induced by eccentric contraction. Therefore, our study provides information for reconsidering rehabilitation and training programs.