2013 Volume 11 Pages 54-61
The purpose of this study was to investigate the effects of fatigue on ground reaction forces and leg kinetics during all-out 600 m running. Eight male middle-distance runners were asked to perform two kinds of running, i.e. an all-out 600 m run and a non-fatigued 80 m run with the same velocity as at the 550 m mark of the 600 m run. Their running motion was videotaped and the ground reaction forces were measured at the 150 m and 550 m marks of the 600 m run and at the 50 m mark of the 80 m run. The step length, ground reaction forces, ankle plantar flexion torque, and knee extension torque of the support leg decreased due to fatigue. The hip joint torque of the recovery leg decreased due to the difference in running speed rather than fatigue. From these results, we suggest that in the final stage of 800 m race, a runner should not try to extend the step length by thrusting against the ground with the support leg but should maintain the step time as much as possible by moving the recovery leg quickly.