Objectives To evaluate the long-term effects of regular moderate or vigorous intensity exercise on blood pressure and blood lipids in previously sedentary older women.Design Subjects were randomly assigned to either a supervised centre-based (CB) or a minimally supervised home-based (HB) exercise program, initially for 6 months. Within each program, subjects were further randomized to exercise either at moderate (40-55% heart rate reserve, HRres) or vigorous intensity (65-80% HRres). After 6 months, all groups continued a HB moderate or vigorous exercise program for another 12 months.Methods Healthy, sedentary women (aged 40-65 years) (n = 126) were recruited from the community. Subjects exercised three times per week for 30 min. They were evaluated at baseline, 6,12 and 18 months.Results There was a significant fall of 2.81 mmHg in systolic blood pressure (P = 0.049) and 2.70 mmHg in diastolic blood pressure (P = 0.004) after correction for age and baseline values with moderate exercise, but not with vigorous-intensity exercise. When this analysis was repeated with the change in body mass included, the results were unchanged. After correction for potential confounding factors, there was a significant fall in total cholesterol and low density lipoprotein cholesterol with vigorous but not moderate exercise at 6 months (P <0.05) but not at 18 months.Conclusions In this largely normotensive population of older women, a moderate, but not vigorous exercise program, achieved sustained falls in resting systolic and diastolic blood pressure over 18 months. The study demonstrates that in older women, moderate intensity exercise is well accepted, sustainable long-term and has the health benefit of reduced blood pressure. (C) 2001 Lippincott Williams & Wilkins.