THE EFFECT OF FLYWHEEL INERTIA ON SHORT-TERM CYCLING POWER OUTPUT IN CHILDREN973

Abstract

Short-term cycling power output can be measured by the Force-Velocity test. In this actual method, power is calculated according to the product of frictional load and velocity. However, this method does not take into account the flywheel inertia during the acceleration. It was hypothesized that Force-velocity without inertia (F-Vwt) underestimates maximal cycling power. The purpose of this study therefore was to calculate power which includes flywheel inertia (F-Vt) and to compare the data with the “classical” method. Twenty-one children (11 boys and 10 girls) aged 13.1 ± 0.6 years participated in the study. The cycle ergometer was specially adapted for children: optimal saddle height and shorter crank length. The results showed that maximal power produced with F-Vt was significantly higher (+ 20%, p<0.01) when compared with F-Vwt (cf. figure). Moreover, the F-Vt method needs only one or two braking loads to calculated maximal power. This protocol is not only less time consuming but also limits muscular fatigue. In conclusion, the F-Vt method, compared with the F-Vwt method, measures consistently maximal short-term cycling power and is therefore useful in pediatric exercise testing.