Influence of Pedalling Effectiveness on the Inter-Individual Variations of Muscular Efficiency in Cycling

The aim of this study was to determine if inter-individual differences in crank torque production and/or pedalling effectiveness influence the variations of muscular efficiency observed among subjects in cycling. Eleven subjects performed a 5 minutes steady state cycling at 160 Watts at 80 revolutions per minute. Gross (GE) and net (NE) muscular efficiency, angular impulses and pedalling effectiveness during the whole pedal revolution (IF360) and during the downstroke phase (IE180) were investigated. Angular impulses were not related to either VO2 or the muscular efficiency. IE360 was not correlated with either VO2 or muscular efficiencies, while IE180 was significantly negatively correlated with VO2 (r(2) = 0.51) and positively related with NE (r(2) = 0.49). The inter-individual differences in crank torque production, as investigated by angular impulse values, did not explain inter-individual differences in muscular efficiency. The lack of relationships between VO2 or muscular efficiencies and IE360 could be due to the fact that IE360 is equally influenced by both low and high pedal forces produced during the upstroke and downstroke phases, respectively, while metabolic energy is mainly consumed during high pedal forces of the downstroke phase. Finally, when measured during the downstroke phase, inter-individual differences in pedalling effectiveness could partly be related to the variations of muscular efficiency observed among subjects in cycling