| Abstract: | The 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 subjects pedalled on two separate occasions for 6 min at 40, 50, 60, 70, 80 and 90 r.p.m. with workload levels representing 30 and 60% of their Vdot]O2max 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 denned as the average of FT/FR over a crank cycle. The result showed no statistically significant change (p<0·05) in Vdot]O2, heart rate and rating of perceived exertion of the FEI as a function of flywheel weight except for the Vdot]O2 at 50 r.p.m. for the light workload. As the r.p.m. increased from 40 to 90 r.p.m., the FEI decreased from 0·5 to 0·35 with the heavy load and from 0·36 to 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 Vdot]O2. |
