Abstract

Maximum-velocity running (sprinting) is an important aspect of many sports, and an effective sprint technique is very important for maximizing running speed. It is generally recognized that during constant-velocity running, a runner's speed is directly related to the horizontal force produced during the foot-ground contact portion of the swing (hip extension) phase. Therefore, an effective sprint technique is the sequence of limb movements that allows for optimum transfer of horizontal force to the ground with the least energy expenditure during the foot-ground contact phase. Energy expenditure is less when the resultant muscle forces applied during sprinting culminate in large horizontal forces at the footground interface with little or no energy being used to control unnecessary movements or muscle force imbalances. Thus, using resistance training to prevent unnecessary movement of core regions of the body (the pelvis, for example) and to minimize muscle strength imbalances reduces energy expenditure and ultimately improves sprinting speed, efficiency, or both. A second way to increase running velocity is to improve the power-producing ability of the muscles responsible for providing force against the ground during running. Because power is a function of both force and velocity (or strength and speed), increasing an athlete's strength should improve that athlete's ability to produce power. Resistance training can be an effective training method for improving a sprinter's strength. Given that adaptations to resistance training have been shown to be specific to the constraints of training exercises, those exercises that mimic the sprint-running technique may be more beneficial than "traditional" resistance-training exercises in improving sprint-specific strength. Although movements at the knee and ankle have some influence on the horizontal force produced at foot-ground contact, this article describes resistance-training exercises that improve the strength and balance of muscles that act at the hip. Verf.-Referat