The study reinforces the importance of ground reaction force GRF) and describes how athletes are able to apply greater amounts of mass-specific force to the ground in the shortest possible time.
Sprint running performance can be investigated relatively simply at the whole-body level by examining the timing of the phases of the stride and the forces applied to the ground in relation to a runners body weight. Research using this approach has been used to address a number of basic questions regarding the limits and determinants of human running speed. The primary differentiating factor for the top speeds of human runners is how forcefully they can strike the ground in relation to body mass. A general relationship between mass-specific force application and maximum running speeds results from the similar durations of the aerial and swing phases of the stride for different runners. Recent work has elucidated the mechanism by which faster runners are able to apply greater mass-specific ground forces in the very brief foot-ground contact times sprinting requires.
The amount of force an athlete can apply to the ground in relation to body weight and the speed with which the force can be applied (ground contact time) is a key factor in improving speed during each of the four phases of a short sprint (the start, acceleration, maximum speed, and deceleration phase). Both the amount of force production and the speed of force application can be improved with proper training.
Weyand, Peter (2017) “FORCE, MOTION, SPEED: A GROUNDED PERSPECTIVE ON HUMAN RUNNING PERFORMANCE,” ISBS Proceedings Archive: Vol. 35 : Iss. 1 , Article 289. Available at: https://commons.nmu.edu/isbs/vol35/iss1/289