title: Cycling efficiency in trained male and female competitive cyclists.
abstract: The aim of this study was to examine differences in cycling efficiency between competitive male and female cyclists. Thirteen trained male (mean ± SD: 34 ± 8 yr, 74.1 ± 6.0 kg, Maximum Aerobic Power (MAP) 414 ± 40 W, VO2max 61.3 ± 5.4 ml·kg(-1)·min(-1)) and 13 trained female (34 ± 9 yr, 60.1 ± 5.2 kg, MAP 293 ± 22 W, VO2max 48.9 ± 6.1 ml·kg(-1)·min(-1)) competitive cyclists completed a cycling test to ascertain their gross efficiency (GE). Leg and lean leg volume of all cyclists was also measured. Calculated GE was significantly higher in female cyclists at 150W (22.5 ± 2.1 vs 19.9 ± 1. 8%; p < 0.01) and 180W (22.3 ± 1.8 vs 20.4 ± 1.5%; p = 0.01). Cadence was not significantly different between the groups (88 ± 6 vs 91 ± 5 rev·min(-1)). Lean leg volume was significantly lower for female cyclists (4.04 ± 0.5 vs 5.51 ± 0.8 dm(3); p < 0.01) and was inversely related to GE in both groups at 150 and 180W (r = -0.59 and -0.58; p < 0.05). Lean leg volume was shown to account for the differences in GE between the males and females. During an "unloaded "pedalling condition, male cyclists had a significantly higher O2 cost than female cyclists (1.0 ± 0.1 vs 0.7 ± 0.1 L·min(-1); p < 0.01), indicative of a greater non-propulsive cost of cycling. These results suggest that differences in efficiency between trained male and female cyclists can be partly accounted for by sex-specific variation in lean leg volume. Key pointsDifferences in GE exist between male and female cyclists.Males have a higher oxygen cost of "unloaded "cycling, as predicted by the intercept of the O2 cost-power output relationshipThis suggests that in addition to work rate, leg volume/mass may be an important determinant of observed differences in oxygen cost and therefore GE, between male and female competitive cyclists.
authors.affiliation: Centre for Sports Studies, University of Kent , Chatham Maritime, Chatham, Kent UK.
authors.forename: James
authors.initials: J
authors.lastname: Hopker
authors.forename: Simon
authors.initials: S
authors.lastname: Jobson
authors.forename: Helen
authors.initials: H
authors.lastname: Carter
authors.forename: Louis
authors.initials: L
authors.lastname: Passfield
keywords: Gross efficiency; endurance performance; leg volume; power output; sex-related differences