MAXIMAL POWER-VELOCITY RELATIONSHIPS IN ADULT AND ADOLESCENT MALES DURING ISOKINETIC CYCLING

Abstract

836 Comparative studies of power output in children and adults have used cycle ergometers designed for adults which cannot control velocity or inertial resistance. The purpose of this study was to compare the power-velocity relationship in adolescent and adult males using a specially constructed isokinetic cycle ergometer. Twelve boys (mean age 14 ±0.5 yrs) and 12 men (mean age 28.8 ±4.2 yrs) underwent a series of between seven and ten 6 sec sprints at fixed pedal velocities ranging from 80 to 170 rev·min-1. Each 6 sec sprint was separated by a 5 min rest period. The effective forces exerted on the cranks were measured by strain gauges, and together with crank speed recorded by a computer. Mean power for the first 5 seconds (MP5s) and the highest mean power for a single complete revolution (MPmax) were computed. Quadratic equations were fitted to these data and differentiated to provide the velocity required to optimise power output for both MP5s and MPmax. Men's MP5s and MPmax (999.5 ±141.7 and 1080.7 ±155.1 W) were significantly higher (p<0.05) than boys (682.4±149.3 and 773.3 ±168.1 W). There were no significant differences in the optimal velocity at MP5s and MPmax for men (123 ±8 and 126 ±8 rev·min-1) or boys (114 ±18 and 121±10 rev·min-1). Allometrically scaled data to account for differences in body mass, revealed common exponents for MP5s (1.0 SE 0.14) and MPmax (1.02 SE 0.16) and the absolute power differences between the men and boys became non-significant (p>0.05). These results reveal a similarity of optimal muscle velocity to generate MP5s and MPmax for men and boys, but no significant difference in muscle power when allometrically scaled for body mass.