Combined oral contraceptives do not influence post-exercise hypotension in women

The aim of the present study was to examine the pattern of cardiovascular recovery from exercise in 15 women (age, 20.3 +/- 1.4 years; body mass, 61.5 +/- 4.3 kg) across two phases of oral contraceptive (OC) use: 21 days of consumption and 7 days of withdrawal. Cardiovascular recovery was measured in the supine position for 60 min following 30 min of exercise at 60% maximal rate of oxygen consumption (VO2,max). Central and peripheral haemodynamics were assessed during consumption and withdrawal of the OC pill using occlusion plethysmography, Doppler flowmetry and echocardiography. Significant hypotension occurred following exercise (P < 0.05), returning to baseline values after 60 min. The peak hypotension occurred 5 min into recovery. Cardiac output and heart rate were elevated for 60 min following exercise (P < 0.05), whilst stroke volume remained at baseline values. Heart rate was greater throughout recovery during consumption compared to withdrawal (P < 0.05); however, although there was a trend for greater responses during consumption, phase of OC use did not affect the other central cardiovascular variables (P > 0.05). Post-exercise blood flow parameters were not significantly affected by exercise or OC phase; however, calf blood flow was greater, and resistance to flow lower during consumption (P > 0.05). The pattern of post-exercise fluctuations in cardiovascular parameters may differ from those seen in men, whilst oestrogen variation may influence research findings.