EXERCISE VENTILATORY RESPONSE TO UPRIGHT AND AERO-POSTURE CYCLING

The aero-cycling posture has become increasingly popular among cyclist s. Because of the potential for altered lung mechanics in the aero-cyc ling posture, the ventilatory and gas exchange profiles of 10 moderate ly trained males (31.1 +/- 6.3 yr, mean +/- SD) exercising on a cycle ergometer in the upright posture (UC) and aero-cycling (AC) posture we re studied. Exercise consisted of 3-min work stages with 50-W incremen tal changes until volitional exhaustion. Ventilatory and gas exchange responses to exercise were averaged each minute. Maximal oxygen consum ption (54.3 +/- 6.3 vs 53.4 +/- 6.9 ml.kg-1.min-1) in the UC and AC we re not significantly different. Maximal values for ventilation (132.5 +/- 32.3 vs 128.0 +/- 28.7 l . min-1), tidal volume (2.7 +/- 0.5 vs 2. 6 +/- 0.3 l . br-1), breathing frequency (50.0 +/- 8.0 vs 47.0 +/- 5.0 br.min-1), and submaximal ventilatory and heart rate responses in the UC were not significantly different compared with the AC. No signific ant difference existed between postures for mean inspiratory flow and inspiratory duty cycle at comparable submaximal power outputs. These r esults indicate that at absolute power outputs, ventilatory responses, as determined by respiratory pattern and timing, and metabolic cost, were similar in the UC and AC. Thus, the AC does not impair physiologi c responses to high intensity exercise.