The effect of resistance and combined training on biochemical markers of bone formation and femoral bending strength of osteoporotic male rats

There is a little information available regarding the effect of resistance and combined training on biomechanical response of bone in osteoporosis condition. This study evaluated the effect of combined training compared to resistance training on bone formation markers and femoral mechanical strength of osteoporotic male Rats. Among forty male Wistar rats, 8 rats were selected as healthy group, then osteoporosis were induced by intraperitoneal injection of 20% alcohol during 3 weeks for other rats. Osteoporotic rats were divided into 4 groups as: baseline, resistance, combined and control. The resistance training protocol consisted of 8 series of climbing activity on the vertical ladder with weights tied to animal tail. Combined group completed the both of resistance and endurance protocol (60 min/day, 12 m/min speed). After completing 12 weeks of exercisetrainings (5 days a week), the blood samples were collected and serum levels of osteocalcin and bone specific alkaline phosphatase was measured by ELISA method. Execised left femurs were examined by three point bending test to obtain the maximum force and stiffness. The data were analyzed by one way-ANOVA and Tukey post hoc tests. A p value (0.05) was set for data statistical analysis. Two groups of the combined and resistance training showed a significantly increased on all measured parameters versus to control group (p<0.05). The effect of combined training on serum of bone specific alkaline phosphatase (p=0.04) and bone mechanical strength (P=0.0001) was more significant than resistance training. Perhaps the combined training provides more protection against of osteoporosis compared to resistance training.