THE VALIDITY OF ISOKINETIC KNEE EXTENSOR ENDURANCE MEASUREMENTS WITH REFERENCE TO TREADMILL RUNNING CAPACITIES

The validity of isokinetic knee extensor endurance measurements with r eference to treadmill running capacities was investigated. Nine male e lite middle-distance runners completed a test consisting of 100 repeti tive maximal eccentric and 100 concentric knee extensor actions where peak torque (Nm) and work (I) were measured, On a different day, subma ximal and maximal tread mill tests were performed. Stepwise regression analysis was applied to determine the isokinetic variables with the g reatest influence on the selected treadmill running capacities, includ ing submaximal oxygen uptake (VO2) and maximal blood lactate, Eccentri c total work was significantly and negatively related to sub-maximal V O2 at all three running velocities investigated (12, 14, and 15 km . h (-1)). The R(2) values ranged from 0.48-0.59 for VO2 ml . kg(-0.75). m in(-1), indicating that 48-59% of the variability in VO2 ml . kg(-0.75 ). min(-1) could be accounted for by eccentric total work, The corresp onding R(2) values for VO in ml . kg(-1). min(-1) were 0.50-0.58, Conc entric relative endurance was significantly and negatively related to maximal blood lactate (R(2) = 0.73). This study has shown that isokine tic knee extensor endurance measurements of eccentric total work and c oncentric relative endurance are substantially related to measures of treadmill running capacity, as expressed by submaximal VO2 and maximal blood lactate. It is suggested that these isokinetic measures may be used to evaluate specified running capacities in male elite middle-dis tance runners.