Breathing strategy in master athletes and untrained elderly subjects according to the incremental protocol.

To analyze the influence of step-duration protocol (1 vs. 3 min) on breathing strategy according to the physical fitness of healthy elderly subjects, this study compared the ventilatory responses and exercise tidal flow-volume loops (ETFVL) at the first and second ventilatory thresholds (VT(1) and VT(2)). Nineteen master athletes (mean age (+/- SD), 63.1 +/- 3.2 y; (.)VO(2)(max), 41.5 mL x (min x kg)(-1)) and 8 untrained elderly subjects (age, 65.5 +/- 2.3 y; (.)VO(2)(max), 25.8 mL x (min x kg)(-1)) performed 2 exhaustive exercise tests on a cycle ergometer. In untrained subjects, at VT(1) and VT(2), no significant difference was measured in ventilatory responses and ETFVL between protocols. Master athletes, at VT(2), presented a significantly higher (.)VCO(2) (P < 0.01), ventilation ((.)VE; P < 0.01), breathing frequency (f(b); P < 0.05), tidal volume relative to inspiratory capatcity (V(t)/IC) (P < 0.01),V(t) relative to forced vital capacity (V(t)/FVC; P < 0.05), and lower inspiratory reserve volume relative to FVC (IRV/FVC; P < 0.01) during the 1 min protocol than during the 3 min protocol. Master athletes, at maximal exercise, expressed significantly higher (.)VCO(2) (P < 0.01) and dyspnea (P < 0.05) with the shorter protocol. We concluded that, in untrained subjects, neither incremental exercise test had an impact on respiratory responses during exercise. Nevertheless, in master athletes, breathing strategy seems to be protocol dependent. The short test induced higher mechanical ventilatory constraints and dyspneic feeling than the long protocol, which could be explained by a higher (.)VE itself linked to a greater (.)VCO(2) and a higher blood lactate concentration.