Ventilatory patterns differ between maximal running and cycling

- Cardiopulmonary responses to exercise depend upon the mode.
- Specifically the ventilatory responses typically differ.
- We compared ventilatory strategies between exercise modes within the same group of trained men.
- We demonstrated operating lung volumes were significantly greater while cycling.
- Posture may be the cause for the observed difference in operating lung volumes between modes.

To determine the effect of exercise mode on ventilatory patterns, 22 trained men performed two maximal graded exercise tests; one running on a treadmill and one cycling on an ergometer. Tidal flow-volume (FV) loops were recorded during each minute of exercise with maximal loops measured pre and post exercise. Running resulted in a greater VO2peak than cycling (62.7 ± 7.6 vs. 58.1 ± 7.2 mL kg−1 min−1). Although maximal ventilation (VE) did not differ between modes, ventilatory equivalents for O2 and CO2 were significantly larger during maximal cycling. Arterial oxygen saturation (estimated via ear oximeter) was also greater during maximal cycling, as were end-expiratory (EELV; 3.40 ± 0.54 vs. 3.21 ± 0.55 L) and end-inspiratory lung volumes, (EILV; 6.24 ± 0.88 vs. 5.90 ± 0.74 L). Based on these results we conclude that ventilatory patterns differ as a function of exercise mode and these observed differences are likely due to the differences in posture adopted during exercise in these modes.