ISOKINETICS AND EXERCISE SCIENCE, vol.16, no.2, pp.87-92, 2008 (SCI-Expanded)
The purpose of this study was to investigate the relationship between, isokinetic knee strength, anaerobic performance and sprinting ability in American football players. Twenty-eight male amateur American football players participated in this study voluntarily. Knee extension and flexion strengths were evaluated at 60, 150 and 240 degrees/s, anaerobic performance was evaluated by Wingate anaerobic power test and sprint ability was determined by single-(20 m) and repeated-sprint ( 12 x 20 m) tests. Extension strength was significantly correlated with peak and mean power in all contraction velocities; however the only significant correlation between flexion strength and peak power was indicated at 240 degrees/s. In the case of sprinting ability, there was a significant but weak correlation between 240 degrees.s(-1) knee flexion strength and percentage of performance decrement from 10-20 m (r = 0.381, p < 0.05). No measure of strength was significantly related to single- sprint and other measures of repeated-sprint ability (p > 0.05). Hence, although maximal knee extension strength is a crucial component in anaerobic performance of American football players, lack of its association with single- and repeated-sprint performance indicates that factors other than strength might be involved in single- and repeated-sprint performance in this group of athletes.