Breathing pattern in highly competitive cyclists during incremental exercise

The purpose of our investigation was to analyse the breathing patterns of professional cyclists during incremental exercise from submaximal to maximal intensities. A group of 11 elite amateur male road cyclists [E, mean age 23 (SD 2) years, peak oxygen uptake ((V)over dot O-2peak) 73.8 (SD 5.0) ml . kg(-1) min(-1)] and 14 professional male road cyclists [P, mean age 26 (SD 2) years, ((V)over dot O-2peak) 73.2 (SD 6.6) ml . kg(-1) min(-1)] participated in this study. Each of the subjects performed an exercise test on a cycle ergometer following a ramp protocol (exercise intensity increases of 25 W . min(-1)) until the subject was exhausted. For each subject, the following parameters were recorded during the tests: oxygen consumption ((V)over dot O-2), carbon dioxide output ((V)over dot CO2). pulmonary ventilation ((V)over dot E), tidal volume (V-T), breathing frequency (f(b)), ventilatory equivalents for oxygen ((V)over dot (E) . (V)over dot O-2(-1)) and carbon dioxide ((V)over dot (E) . (V)over dot CO2-1), end-tidal partial pressure of oxygen and partial pressure of carbon dioxide, inspiratory (t(I)) and expiratory (t(E)) times, inspiratory duty cycle (t(I)/t(TOT), where t(TOT) is the time for one respiratory cycle), and mean inspiratory flow rate (V-T/t(I)). Mean values of (V)over dot (E) were significantly higher in E at 300, 350 and 400 W (P < 0.05, P < 0.05 and P < 0.01, respectively); f(b) was also higher in E in most moderate-to-maximal intensities. On the other hand, VT showed a different pattern in both groups at near-to maximal intensities, since no plateau was observed in P. The response of t(I) and t(E) was also different. Finally, V-T/t(I) t(I) and t(I)/t(TOT) showed a similar response in both P and E. It was concluded that the breathing pattern of the two groups differed mainly in two aspects: in the professional cyclists, (V)over dot (E) increased at any exercise intensity as a result of increases in both V-T and f(b), with no evidence of tachypnoeic shift, and t(E) was prolonged in this group at high exercise intensities. In contrast, neither the central drive nor the timing component of respiration seem to have been significantly altered by the training demands of professional cycling.