Abstract

This study was undertaken to examine the relationship between energy expenditure and work rate on a bicycle ergometer in five sprinters and five distance runners who differed in maximal oxygen uptake (VO2max) and type of training. Each subject performed at work rates of 30, 60, 90, 120, and 150 watts (W). The relationship between energy expenditure and work rate was most accurately described by a quadratic curve for both groups. Delta efficiency (delta work accomplished delta energy expended x 100 ) decreased as work rate increased. Statistical analyses revealed no significant differences between groups in delta efficiency at the same work rate or at the same relative work rate. These results suggest that differences in VO2max andor type of training have little or no causal effect on the decrease in delta efficiency with increasingwork rate. The observed decrease in delta efficiency may be due to increases in metabolism not directly related to the performance of the external work or to an increasing amount of unmeasured work as work rate increases on a bicycleergometer. Verf.-Referat