Abstract des Autors

To examine whether the menstrual or monophasic oral contraceptive cycle phases affect submaximal (oxygen uptake (O2) kinetics, maximal lactate steady-state (MLSS)) and maximal (O2max, time-to-exhaustion (TTE)) responses to exercise in healthy, active women. During the mid-follicular or inactive-pill phase and the mid-luteal or active-pill phase of the respective menstrual or oral contraceptive cycle, 15 non-oral contraceptive users (mean and standard deviation (SD) (+/-): 27 +/- 6 years; 171 +/- 5 cm; 65 +/- 7 kg) and 15 monophasic oral contraceptive users (24 +/- 4 years; 169 +/- 10 cm; 68 +/- 10 kg) performed: one O2 kinetics test; one ramp-incremental test; two to three 30-minute constant-load cycling trials to determine the power output corresponding to MLSS (MLSSp), followed by a TTE trial. The phase of the menstrual or oral contraceptive cycle did not affect the time constant of the O2 kinetics response (τO2) (mid-follicular, 20 +/- 5 seconds and mid-luteal, 18 +/- 3 seconds; inactive-pill, 22 +/- 8 seconds and active-pill, 23 +/- 6 seconds), O2max (mid-follicular, 3.06 +/- 0.32 L/min and mid-luteal, 3.00 +/- 0.33 L/min; inactive-pill, 2.87 +/- 0.39 L/min and active-pill, 2.87 +/- 0.45 L/min), MLSSp (mid-follicular, 181 +/- 30 W and mid-luteal, 182 +/- 29 W; inactive-pill, 155 +/- 26 W and active-pill, 155 +/- 27 W), and TTE (mid-follicular, 147 +/- 42 seconds and mid-luteal, 128 +/- 54 seconds; inactive-pill, 146 +/- 70 seconds and active-pill, 139 +/- 77 seconds) (P > .05). The rate of perceived exertion (RPE) at minute 30 of the MLSSp trials was greater in the mid-follicular phase (6.2 +/- 1.5) compared with the mid-luteal phase (5.3 +/- 1.4) for non-oral contraceptive users (P = .022). The hormonal fluctuations between the menstrual and oral contraceptive cycle phases had no detectable effects on submaximal and maximal exercise performance, even when RPE differed.