Effects of endurance training on the breathing pattern of professional cyclists

The aim of this longitudinal study was to clarify the changes induced by en durance training on the breathing pattern of 13 professional cyclists (age +/- SD: 24 +/-2 years; (V)over dot O(2)max similar to 75 ml.kg(-1).min(-1)) during the three periods (rest, precompetition, and competition) of a spor ts season. Both the volume and the intensity of training were quantified du ring these periods. in each session (corresponding to each of the three per iods) all subjects performed (1) a pulmonary function test (to measure forc ed vital capacity [FVC], peak expiratory flow [PEF], and maximal voluntary ventilation [MVV]), and (2) a vamp test until exhaustion on a cycle ergomet er (workload increases of 25 W min-l). The following variables were recorde d every 100W until the end of the tests: pulmonary ventilation ((V)over dot E, in l.min(-1) BTPS), tidal volume (VT, in lBTPS), breathing frequency (f (b), in breaths.min(-1)), 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 ), inspiratory (Tl) and expiratory (TE) times (s), ratio of TI to total res piratory duration or inspiratory "duty cycle" (Tl/TTOT), and mean inspirato ry flow rate (VT/Tl, in l .s(-1)). The results showed no changes in any of these variables (p >0.05) between the three periods of study, despite signi ficant changes in training loads (i.e., increases in the volume and/or inte nsity of training throughout the season). These findings suggest that endur ance conditioning does not alter the breathing pattern of professional cycl ists during an incremental exercise test.