Poor relationship between strength and power qualities and agility performance.

Despite the important role of agility in successful performance in many team and racket sports, little is known about their physiological and muscular basis. The aim of this study was to examine the relationship between the leg extensor strength and power and agility performance.Male physical education students (n=76) were assessed by means of 3 typical agility performance tests (lateral stepping, 20-yard shuttle run, and slalom run). Six tests of leg extensor strength (isoinertial squat, isometric squat, and one-leg rising) and power (squat jump power, hopping power, and standing long jump distance) were also obtained.The correlations between strength and power, and each agility performance were generally low. As a consequence, the multiple correlation coefficients between strength and power predictors and agility, albeit significant (P<0.01), were also rather low (r=0.33, 0.44, and 0.35 for the lateral stepping, 20-yard shuttle run, and slalom run, respectively). The highest relationship with each of the agility tests was revealed by the one-leg rising test (r within -0.3 and -0.44; P<0.02).The results of the present study suggest that most of the multijoint leg extensor strength and power measures are poor predictors of agility in physically active men. Thus, the effects of interventions aimed towards the improvement of functional movement performance may not require evaluation by means of the common tests of muscular strength and power. A more specific approach including both the functional strength tests and functional movement performance tests could be recommended instead.