Physically active postmenopausal women have a lower incidence of coronary heart disease (CHD) than their more sedentary peers, but little information is available concerning the responsible mechanisms. The primary aim of this study was to test the hypothesis that physically active post-menopausal women demonstrate more favorable levels of hemostatic, metabolic, and androgenic CHD risk factors than less active control subjects. If so, a secondary aim was to determine which of the characteristics associated with a physically active lifestyle, ie, low body fat, a high-carbohydrate/low-fat diet, high maximal aerobic capacity (aerobic fitness), and high levels of physical activity, are most closely related to this lower risk profile. To address these aims, we compared CHD risk factors in physically very active women (n = 14; age, 55 +/- 2 years) with those in healthy, nonobese sedentary control subjects (n = 17; age, 56 +/- 1 years). Maximal aerobic capacity (fitness) was 83% higher (P < .001) in the physically active women. Concentrations of plasminogen activator inhibitor type 1 activity and tissue plasminogen activator antigen were lower (more favorable) (P < .005) in the physically active women versus control subjects, whereas plasma fibrinogen levels did not differ. The physically active women had lower (P < .01) fasting plasma insulin and glucose concentrations as well as smaller responses to an oral glucose challenge. Both total-body and abdominal fat levels were lower (P < .001) and lipid and lipoprotein profiles were generally more favorable (P < .05) in the physically active women.(ABSTRACT TRUNCATED AT 250 WORDS)