The effect of crank rate on physiological responses and exercise efficiency using a range of submaximal workloads during arm crank ergometry

This study examined the effects of variations in crank rate on physiological responses during submaximal arm ergometry. Fifteen non-specifically trained male subjects volunteered to participate in this study. Each subject undertook a discontinuous arm crank ergometry test (30, 50, 70, 90 W) on three separate occasions using crank rates of 50, 70, and 90 rev·min^-1. Respiratory parameters and heart rate were continuously monitored. An 80-μL capillary blood sample was obtained immediately following each exercise bout for the determination of whole blood lactate. Measures of efficiency were calculated using specific caloric equivalents of oxygen consumption (V̇O₂). Heart rate was lowest (p < 0.05) at 30, 50, and 70 W using 50 rev·min^-1. Values of gross and net efficiency tended to be higher (p < 0.05) using 50 rev·min^-1 at the lower absolute workloads, but no differences (p > 0.05) were observed between the three crank rates at 90 W. No differences (p > 0.05) were observed between crank rates for delta efficiency. This study confirms that variations in crank rate can influence gross and net values of V̇O₂ and exercise efficiency at low absolute workloads, but crank rate ceases to be an influential factor at moderate workloads. Further research is required to identify the specific mechanisms underpinning the observations reported in the present study relating to the interaction between crank rate, workload, and exercise efficiency during arm crank ergometry.