Physiological effects of variations in spontaneously chosen crank rate during sub-maximal and supra-maximal upper body exercises

The aim of the present study was to compare the physiological responses whe n the crank rate was chosen spontaneously (T-s) or set at +/- 10% (T-10%, T +10%) of the freely chosen rate, during two upper body exercises: i) a sub- maximal test (T-SUB) in which intensities ranged from 50 to 80% (118.4 +/- 10.2 to 189.5 +/- 76.3 watts) of maximal power (MP) and ii) a supramaximal test (T-SUPRA) in which power output was set at 110 and 120 % (260.5 +/- 22 .4 and 284.2 +/- 24.4 watts) of MP. Eight nationally and internationally ra nked kayakers, aged 20 +/- 2 years, per formed these tests in which power o utputs were normalised in relation to the maximal power output determined d uring T-MP. In TSUB+10%, oxygen uptake and ventilation were significantly ( P < 0.05) higher than during T-SUB.S. In TSUB+10% and TSUB-10%, energy expe nditure was significantly (P < 0.05) higher and gross and net efficiencies lower than during T-SUB.S. During TSUPRA-10% when the power output was set at 110% of MP, time to exhaustion was significantly higher (P < 0.05) than during T-SUPRA.S. The findings of the present study suggest that upper body exercise performed on an ergocycle should be conducted using the freely an d spontaneously chosen crank rate.