Relation between leisure-time physical activity and blood pressure in older women. Although there is some evidence that physical activity may decrease blood pressure in young and middle-aged women, the physical activity-blood pressure association in older women has rarely been studied. As part of an ongoing community-based study of chronic disease, 641 Caucasian women between the ages of 50 and 89 years had blood pressure measured following the Hypertension Detection and Follow-up Program protocol. They also answered selected Health Interview Survey questions about their leisure-time activity and were classified into categories of light (58%), moderate (24%), heavy (6%), or no physical activity (12%) by the estimated metabolic rate required for each activity. Women who engaged in any physical activity were significantly younger and thinner than sedentary women and had lower fasting and 2-hour postchallenge insulin levels. They did not differ in alcohol consumption, cigarette use, or prevalence of coronary heart disease or diabetes. Rates of systolic and diastolic hypertension were significantly lower in women participating in light, moderate, or heavy physical activity compared with sedentary women. Blood pressure levels decreased with each increase in reported activity intensity (p less than 0.005 for trend), with systolic blood pressure approximately 20 mm Hg lower in the heaviest activity group compared with systolic blood pressure in sedentary women. Intergroup differences remained statistically significant after adjustment for age and body mass index. Although physical activity was associated with lower fasting and 2-hour postchallenge insulin levels (p less than 0.01 for trend), adjustment for insulin levels did not alter blood pressure differences among activity groups. 