The biomechanical changes during high-intensity running to fatigue

Changes in running mechanics during high-intensity running to fatigue remain largely unknown. The purpose of this study was to investigate the changes in kinematics and kinetics during a high-intensity treadmill run to exhaustion. Sixteen national standard male and female middle-distance runners performed a high-intensity run at a constant velocity on an instrumented treadmill. Running speed was based on peak speed during a VO2max test and athletes ran for an average of ~180 s. Motion capture and force data were recorded and compared at four points throughout the run. Peak vertical ground reaction force, peak ankle plantar flexor moments and positive ankle work during stance decreased significantly throughout the run (P< 0.05). On the other hand, positive hip work increased during stance (P< 0.05). The fatigue that occurs during a high-intensity run leads to a redistribution of work from the ankle to the hip during stance.