Effect of Semirecumbent and Upright Body Position on Maximal and Submaximal Exercise Testing

Abstract

The study was designed to determine the effect of upright-posture (UP) versus semirecumbent (SR) cycling on commonly used measures of maximal and submaximal exercise capacity. Nine healthy, untrained men (M age = 27 years, SD = 4.8 years) underwent steady-state submaximal aerobic testing followed by a ramped test to determine maximal oxygen consumption (V_O2max). Anaerobic peak and average power and total work were assessed with the Wingate test. All tests were performed in both SR and UP positions, in random order. Oxygen consumption (V_O2) and ventilation (V_E) at the maximum workrate were lower in the SR position (p < .05). At submaximal workrates (50 W and 100 W), V_O2 and V_E were equivalent in the UP and SR positions, despite differences in tidal volume and respiratory rate (p < .05). There was no difference in peak or average anaerobic power in the two positions. In summary, SR exercise was associated with a reduced V_O2max and a significantly altered ventilatory response to aerobic exercise, with no change in anaerobic power output.