Abstract: Objective To study the influence of exercise fatigue index on different treadmill slope in rats. Methods 32 SD rats were randomly divided into 4 groups: the control group, and 0°-, -15°- and 15°- treadmill slope exercise groups. The model group was given treadmill exercise according to the scheme. Related indexes were detected after 6 weeks training. The serum content of glucose(GLU), blood urea nitrogen(BUN), lactic acid (LA), creatine kinase (CK), hemoglobin (HGB), red blood cell (RBC). Gastrocnemius muscle index and the number of electric shock in the rats were calculated. Results Compared with the control group, there were significant changes in the blood metabolites, energy material and exercise ability during different treadmill slope exercise in the rats. The GLU, HGB and RBC in the peripheral blood samples of each exercise group were significantly lower than those in the control group (P<0.01, P<0.05), and the gastrocnemius muscle index was significantly higher (P<0.01). The serum of LA, BUN concentration and CK activity were significantly increased (P<0.01, P<0.05) in the 15°treadmill and -15°treadmill exercise groups. Compared with the 0° treadmill exercise group, the number of electric shock in the rats were significantly increased in the 15° treadmill and -15° treadmill exercise groups (P<0.05). HE staining showed that the gastrocnemius muscle cells of rats had a tendency of swelling and injury after exercise. Conclusions At 15°treadmill exercise groups, the exercise fatigue model replication of rats was better than that of 0° or -15°treadmill exercise groups.

Key words: Exercise-induced fatigue, Treadmill slope, Exercise ability, Rat