Abstract:

BACKGROUND: Acute violent exercise can result in oxidative stress reaction. Reactive oxygen species mitochondrioa cause oxidative stress and calcium ion over-loading, leading to the function of skeletal muscle and body fatigue. However, the mitochondra can have adaptive changes following long-term regular exercise, which can protect body from damage of over-produced reactive oxygen species.   
OBJECTIVE: To investigate the effects of different exercise time and methods on the activities of skeletal muscle mitochondrial respiratory chain complexesⅠ and Ⅳ.
METHODS: A total of 48 healthy male SD rats were randomly divided into normal control, anaerobic, alternating and aerobic exercise groups. After 2, 4 and 6 weeks of exercising, the rats were sacrificed and skeletal muscle mitochondria were isolated by differential centrifugation. The activities of mitochondrial respiratory chain complexes Ⅰ and Ⅳ were measured by spectrophotometry.
RESULTS AND CONCLUSION: The activitie of complexes Ⅰ and Ⅳ of the aerobic and alternating exercise groups increased with time after exercising, while those of the anaerobic group were increased before 6 weeks, and then decreased afterwards. The results suggest that aerobic exercise can enhance the activities of rat mitochondrial respiratory chain complexes Ⅰ and Ⅳ during endurance exercise. Anaerobic exercise can enhance the activities only in short term. Longer anaerobic exercise may damage mitochondrial complexes, resulting in decreased energy generation and body fatigue.