Relation between power and endurance for treadmill running of short duration

Abstract

An exercise test was devised to investigate the relationship between power and endurance for treadmill running. The subjects were 19 males aged 21-25 yr (11 distance runners and 4 sprinters of provincial grade, and 4 non-competitive runners). Each subject ran to exhaustion on a treadmill at 15kmhr−1at five different inclinations (31%-9%), giving maximum performance times in the range 10s to 3 min. An iterative least-squares procedure was used to fit the following exponential model to each subject's data: I1= I∞+ (I0−I∞)exp(−t/τ) where I1, I0and 1∞are inclinations at time t = t, t = 0 and t → ∞, and τ is a time constant. The fit was excellent (r 2= 0.96− 1.00). I0and 1∞are interpreted as measures of maximum anaerobic (instantaneous) and maximum aerobic (continuous) power respectively. Inclinations corresponding to performance times of 10-180s (I10−I180) were calculated from these parameters. Test-retest reliability was highest for I0-I30(intraclass r= 0.97−0.94), lower for I60-I∞(r= 0.89−0.84), and lowest for τ (r= 0.78). Good correlations were observed between I0-I30and peak power in a 30s all-out test on a cycle ergometer (r= 0.73−0.81), and between I180, I∞and maximum oxygen consumption (r= 0.87, 0.81). The test may be useful for ranking or monitoring running performance for events of up to 1 min duration.