Stig Leirdal1, Gertjan Ettema. 1. Human Movement Science Programme, Norwegian University of Science and Technology, Trondheim, Norway. stig.leirdal@svt.ntnu.no
Abstract
PURPOSE: Because cycling is an extreme endurance sport, energy saving and therefore efficiency is of importance for performance. It is generally believed that gross efficiency (GE) is affected by pedaling technique. A measurement of pedaling technique has traditionally been done using force effectiveness ratio (FE; ratio of effective force and total force). The aim of the present study was to investigate the relationship among GE, FE, and a new technique parameter, dead center (DC) size in competitive cyclists. METHOD: Twenty-one competitive cyclists cycled for 10 min at approximately 80% VO(2max) at a freely chosen cadence (FCC). GE, FE ratio, and DC size were calculated from oxygen consumption and propulsive force recordings. RESULTS: Mean work rate was 279 W, mean FCC was 93.1 rpm, and mean GE was 21.7%. FE was 0.47 and 0.79 after correction for inertial forces; DC was 27.3% and 25.7%, respectively. DC size correlated better with GE (r = 0.75) than with the FE ratio (r = 0.50). Multiple regressions revealed that DC size was the only significant (P = 0.001) predictor for GE. Interestingly, DC size and FE ratio did not correlate with each other. CONCLUSIONS: DC size is a pedaling technique parameter that is closely related to energy consumption. To generate power evenly around the whole pedal, revolution may be an important energy-saving trait.
PURPOSE: Because cycling is an extreme endurance sport, energy saving and therefore efficiency is of importance for performance. It is generally believed that gross efficiency (GE) is affected by pedaling technique. A measurement of pedaling technique has traditionally been done using force effectiveness ratio (FE; ratio of effective force and total force). The aim of the present study was to investigate the relationship among GE, FE, and a new technique parameter, dead center (DC) size in competitive cyclists. METHOD: Twenty-one competitive cyclists cycled for 10 min at approximately 80% VO(2max) at a freely chosen cadence (FCC). GE, FE ratio, and DC size were calculated from oxygen consumption and propulsive force recordings. RESULTS: Mean work rate was 279 W, mean FCC was 93.1 rpm, and mean GE was 21.7%. FE was 0.47 and 0.79 after correction for inertial forces; DC was 27.3% and 25.7%, respectively. DC size correlated better with GE (r = 0.75) than with the FE ratio (r = 0.50). Multiple regressions revealed that DC size was the only significant (P = 0.001) predictor for GE. Interestingly, DC size and FE ratio did not correlate with each other. CONCLUSIONS:DC size is a pedaling technique parameter that is closely related to energy consumption. To generate power evenly around the whole pedal, revolution may be an important energy-saving trait.