The effect of a high intensity bout of exercise on maximum expiratory pressure in highly trained individuals
Ten well trained cyclists were studied and compared with 12 untrained subjects from a previous study to determine the effects of a high intensity, constant workload bout of cycling on maximum expiratory pressure (Pemax). Subjects completed a graded exercise test on a Monark cycle ergometer while expired gases were collected to determine maximal oxygen consumption (VO2max). Subjects then returned on a second day when measurements of each subject's Pemax, were made prior to riding at the workload corresponding to 90% of their VO2max until exhaustion. Measurements of expiratory pressure (Pe) were then made immediately post exercise (PeIPE), one minute post exercise (Pe1MIN), three minutes post exercise (Pe3MIN), and five minutes post exercise (Pe5MIN). Trained cyclists had a significantly higher Pemax (x = 116.43 ± 7.76 mmHg) than did untrained subjects (x = 65.75 ± 7.09 mmHg). Also trained cyclists generated a higher absolute Pe throughout recovery than did the untrained subjects. Although expiratory pressure decreased after exercise in both groups, the relative change in Pe over the recovery period, expressed as a percentage of Pemax, was not different between trained and untrained. PeIPE was decreased to 81.87% ± 3.12 of Pemaxin trained subjects and 82.35% ± 2.85 in untrained subjects (p < .05), recovering somewhat at 1 minute to 89.19% ± 3.59 of Pema, in trained and to 87.74% ± 3.27 in untrained (p < .05) but did not recover to resting levels in either group. Pe3MIN and Pe5MIN remained at the same level as Pe1MIN in both groups. Therefore, a high intensity, short term exercise bout caused expiratory pressure to be decreased in both trained and untrained subjects.