No gender-specific differences in mechanical efficiency during arm or leg exercise relative to ventilatory threshold

The purpose of this study was to determine economy and mechanical efficiency in men and women during both arm cranking (AC) and leg cycling (LC) at 70%, 85%, 100%, and 115% of mode-specific ventilatory threshold (T _vent). Recreationally active men (n=9) and women (n=9) with similar values for %V̇O_2peak at T_vent served as subjects. All subjects performed 5 min of exercise at each intensity of 70%, 85%, 100%, and 115% of T_vent for both AC and LC. Economy was expressed as W/L/min. Gross efficiency (GE) was determined as the ratio of work accomplished to total energy expended (%). Delta efficiency (DE) was determined as the ratio of delta work accomplished to delta energy expended (%). Economy and efficiency during LC were greater than during AC in men and women. During AC or LC exercise, no sex differences were found in either economy (P=0.93 for AC, 0.98 for LC), GE (P=0.88 for AC, 0.75 for LC), or DE (P=0.57 for AC, 0.51 for LC). These findings indicate that men and women show similar economy and efficiency during both AC and LC exercise when subjects have similar %V̇O_2peak at T _vent.