Effect of exercise bicycle cadence and loads on pedaling force and lower extremity EMG

Objective: To compare the pedaling force and lower extremity electromyography (EMG) with different cadences (60, 75, 90 r/min) and diverse cycling intensities (50%, 65%, 80% POV) and study the different influence on exerciser's pedaling force and lower extremity EMG. Methods: Twelve healthy males participated in this study, and underwent two stages. In stage 1 the power output test at VO₂max (POV) was got by cycle ergometer. In stage 2, nine conditions (3 kinds of intensities × 3 kinds of cadences) were completed respectively by using counter-balance design to record the changes for their pedaling force and lower extremity EMG. Results: The negative pedaling work was significantly increased with the cadence increasing, and the appearing time of the peak pedaling force was significantly shifted forward in the cycle. When the crank angle was at 270°, the average increase of the pedaling force with the cadence increasing could obtain 1.84 times higher. In general, the firing rate of lower extremity muscular activation would be increased with the cadence increasing. Conclusions: The cadence has greater effect on the pedaling force and lower extremity EMG. The tendency of pedaling force was shifted forward and the pattern of pedaling force became smoother with the cadence increasing. There are no significant differences among the diverse intensities. Based on the pedaling efficiency in this study, the optimal cadence for untrained people should be 60 r/min.