Critical power of knee extension exercises does not depend upon maximal strength

A possible dependence of critical power (CP) and the Y-intercept of the wor k/exhaustion time relationship (Y-intercept) on maximal muscular strength o f the same muscle group has been studied in nine endurance-trained subjects , seven gymnasts, and seven weight-lifters. CP was calculated as being equa l to the slope of the linear relationship between exhaustion time and the w ork performed at exhaustion on a knee extension ergometer. Y-intercept was equal to the intercept between this relationship and the work axis. The mus cular strength of the knee was evaluated by measuring the torques exerted o n a Biodex knee isokinetic dynamometer at four angular velocities: 0 degree s . s(-1) (T-0), 90 degrees . s(-1) (T-90), 180 degrees . s(-1) (T-180) and 240 degrees . s(-1) (T-240) The results of the present study do not suppor t the hypothesis that CP depends upon maximal strength. Indeed, CP was not correlated with T-0, T-90, T-180 or T-240 (\r\ < 0.01). Y-intercept was sig nificantly and positively correlated only with T-90.