The influence of flywheel weight and pedalling frequency on the biomechanics and physiological responses to bicycle exercise†

Publisher Website
Google Scholar
Abstract
Physiological, subjective and biomechanical effects of altering flywheel weight and pedalling rate on a Quinton Model 870 bicycle ergometer were studied. Steel plates were added to the flywheel to increase its weight to 35.9 kg with a moment of inertia of 1.65 kg m2. A 1.5-kg spoked wheel with a moment of inertia of 0.1 kg m2 was used as the light flywheel. Eight [human] subjects pedalled on 2 separate occasions for 6 min at 40, 50, 60, 70, 80 and 90 rpm with workload levels representing 30 and 60% of their .ovrhdot.VO2 max [maximum O2 uptake] with each flywheel. Force plate pedals were used to measure the total resultant force on the pedals (FR) and the component perpendicular to the crank arm (FT). A force effectiveness index (FEI) was defined as the average of FT/FR over a crank cycle. Results showed no statistically significant change (P < 0.05) in .ovrhdot.VO2, heart rate and rating of perceived exertion of the FEI as a function of flywheel weight, except for the .ovrhdot.VO2 at 50 rpm for the light workload. As the rpm increased from 40-90, the FEI decreased from 0.5-0.35 with the heavy load and from 0.36-0.22 with the light load. Measured physiological, subjective and biomechanical indices did not change significantly with flywheel weight. Increasing the pedalling rate caused a significantly less effective application of forces to the crank arm with only a small change in .ovrhdot.VO2.