Cardiovascular hemodynamics with increasing exercise intensities in postmenopausal women

We sought to determine the cardiovascular responses to increasing exercise intensities in postmenopausal women with different physical activity levels and hormone replacement therapy (HRT) status. Forty-four women (11 sedenta ry, 19 physically active, 14 master athletes; 24 not an HRT, 20 on HRT) com pleted treadmill exercise at 40, 60, 80, and 100% of maximal oxygen consump tion. Oxygen consumption, heart rate, blood pressure, and cardiac output;, determined via acetylene rebreathing, were measured at each exercise intens ity. HRT did not affect; cardiovascular hemodynamics. Stroke volume (SV) de creased significantly between 40 and 100% of maximal oxygen consumption in all groups, and the decrease:did not differ among groups; The greater oxyge n consumption of the athletes at each intensity was due to their significan tly greater cardiac output, which was the result of a significantly greater SV, compared with bath of the less active groups. The athletes had signifi cantly lower total peripheral resistance at each exercise intensity than di d the two less active groups. There were no consistent significant hemodyna mic differences between the physically active and sedimentary women. These results indicate that SV decreases in postmenopausal women as exercise inte nsity increases to maximum, regardless of their habitual physical activity levels or HRT status.