Abstract des Autors

In previous studies decreases in the VO2 slow component were observed after prior heavy exercise. The observed effects after prior low-intensity exercise were rather controversial. The purpose of the present study was to more thoroughly examine the effects of prior low-intensity exercise on the VO2 slow component. Furthermore, it has been suggested that the VO2 slow component may be a determinant of exercise tolerance. Therefore we tested the hypothesis whether an attenuated VO2 slow component induced by prior exercise could affect the time to exhaustion. Ten subjects performed four exercise protocols consisting of heavy cycling exercise (95 % VO2peak) until exhaustion. This constant-load exercise was performed without prior exercise (protocol NPE), or was preceded by 6 min heavy cycling exercise (protocol 6HPE), 12 min low-intensity cycling exercise (protocol 12LPE) or 6 min low-intensity cycling exercise (protocol 6LPE). The VO2 slow component quantified as �VO2(end-2) (669 ± 90 ml/min in NPE) was significantly reduced after heavy as well as low-intensity exercise (respectively 47 %, 29 % and 17 % in 6HPE, 12LPE and 6LPE). This reduction lead to a significantly lower end VO2 in 6HPE and 12LPE. The time to exhaustion (594 ± 139 s in NPE), however, was unaffected by prior exercise rejecting our hypothesis that the attenuated VO2 slow component could improve the capability to sustain exercise performance. Verf.-Referat