Structural and mechanical adaptations of the limb bones to jump training in rats / 体力科学

ABSTRACT

Structural and mechanical adaptations of the femur and tibia to jump and run training were investigated in female Fischer 344 rats. Rats aged 4 weeks were trained for 8 weeks after 1 week of stabilization. In experiment A, the forced run-trained (speed 30 m/min, duration 1 h/day) group was compared with the control group. In experiment B, voluntary run and jump-trained (height 40 cm, 100 times/day) groups were compared with the control group. The limb bones of the jump-trained group had greater cross-sectional areas and greater maximum load in a fracture test than the limb bones of the control group, but there was no significant difference in bone length between the jump-trained group and the controls. The bone adaptations to forced running and voluntary running were similar. The limb bones of both run groups were longer than those of each control group. The cross-sectional areas and the maximum load in the run-trained groups were greater than those in each control group but less than those in the jump-trained group. The present results indicate that bone adaptations to jump training and run training differ and that jump training is more effective for building stronger bones.