Abstract des Autors

Assessments of maximal intensity exercise which determine peak power output on friction-braked cycle ergometers have fallen into two categories: correction procedures which account for changes in momentum of the ergometer's flywheel and optimization procedures which attempt to satisfy muscle force-velocity relationships. The aim of this study was to compare performance in each procedure and so investigate assumptions which underpin the tests. Nineteen males aged 20.9+/-0.4 years and 18 females aged 22.2+/-0.7 years (mean+/-S.E.M.), who were fully accustomed to the procedures, participated in a single experimental protocol. After a 5 min warm-up, the subjects performed four bouts of all-out exercise on a Monark 814E cycle ergometer against randomly assigned loads. The loads were selected to produce peak pedalling rates in the range 100-200 rev/min and each bout lasted 10 s. From the inverse linear relationship between applied load and peak pedalling rate, optimized peak power output (PPopt) and the accompanying pedalling rate (RPMopt) were calculated. One of the bouts used a loading equivalent to 7.5% of body weight and for this bout corrected peak power output (PPcorr) and its corresponding pedalling rate (RPMcorr) were calculated. The PPopt was less than PPcorr in the males (915+/-35 vs 1005+/-32 W) and females (673+/-33 vs 777+/-39 W) (both P<0.001). Similarly, RPMopt was less than RPMcorr (111+/-1 vs 128+/-2 rev/min and 101+/-1 vs 111+/-2 rev/min in the males and females, respectively; P<0.001). The results demonstrate that optimization and correction procedures produce different values of performance. These differences are probably attributable to the mechanical principles which underpin the tests. Verf.-Referat