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

Abstract

The aim of the present study was to compare the physiological responses when the crank rate was chosen spontaneously (Ts) 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 +/- 16.3 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 ranked kayakers, aged 20 +/- 2 years, performed these tests in which power outputs were normalised in relation to the maximal power output determined during T(MP). In T(SUB+10%), oxygen uptake and ventilation were significantly (P< 0.05) higher than during T(SUBxS). In T(SUB+10%) and T(SUB-10%), energy expenditure was significantly (P<0.05) higher and gross and net efficiencies lower than during T(SUBxS). During T(SUPRA-10%) when the power output was set at 110% of MP, time to exhaustion was significantly higher (P<0.05) than during T(SUPRAxS). The findings of the present study suggest that upper body exercise performed on an ergocycle should be conducted using the freely and spontaneously chosen crank rate.