Breathing patterns during progressive incremental cycle and treadmill exercise are different

Perceived breathlessness at comparable minute ventilation (V_E) is higher with cycling than with running. Different use of the upper extremities and chest wall may influence the breathing pattern. It was hypothetized that the relationship between tidal volume (V_T) and V_E throughout progressive incremental exercise is different with the two modes of exercise. Twelve well trained subjects (seven men) 20–25 years had incremental maximal exercise tests on a treadmill and a cycle ergometer on different days in random order. Heart rate, respiratory gases, V_E and V_T were measured on a computerized exercise testing system, and data were averaged over 20 s periods. The V_E?V_T relationship was characterized by maximum V_T, V_T at a V_E of 30 l min^?1 (V_T30), the Hey plot and by a least squares quadratic regression model. The increase in V_T by V_E was steeper and V_T30 was higher with cycling compared to running. V_Tmax was not different, but was achieved at a lower V_E with cycling. Breathing strategies are different with running and cycling in young well trained subjects, and exercise mode must be accounted for in normative studies of breathing pattern.