Background Lifestyle modifications, such as physical activity, are recommended as first-line or adjunctive therapy for hypertension. However, controversy exists regarding the type, amount, and intensity of physical activity for optimal blood pressure lowering. Design and Methods This study evaluated the blood pressure changes in 18 post-menopausal, sedentary, untreated hypertensive women randomized to an individualized 8-week programme of intermittent mode rate-intensity physical activity versus no change in physical activity. The physical activity group was asked to select activities (such as walking) to engage in physical activity for 10 min, three times a day, 5 days per week at an intensity of 50-60% heart rate reserve. Results Independent T-tests were used to compare the difference in resting blood pressure between groups. After 8 weeks, resting blood pressure was 8/5 mmHg lower in the physical activity group (systolic blood pressure, P = 0.006 and diastolic blood pressure, P = 0.059). The between group differences remained significant after adjustment for age, baseline blood pressure and previous use of antihypertensive drug therapy. Conclusion These data show that hypertensive, post-menopausal women who engage in intermittent, moderate-intensity physical activity experience a reduction in blood pressure. (C) 2001 Lippincott Williams & Wilkins.