The effects of walking volume on blood pressure in hypertensive postmenopausal women

The American College of Sports Medicine and the Centers for Disease and Control and Prevention (ACSM-CDC) recommend that 30 minutes of accumulated moderate intensity activity, such as brisk walking, should be performed daily for the attainment of health benefits. However, the effectiveness of these recommendations remain untested, particularly for their efficacy in lowering blood pressure in hypertensive postmenopausal women. Therefore, postmenopausal women with borderline to mild hypertension were randomly assigned to either a 16 kilometer/week (low) walking group (N = 12), 32 kilometer/week walking (high) group (N = 12), or sedentary control group (N = 13). The low and high groups walked an average of 13 and 22 kilometers/week respectively, above their baseline walking activity for 12 weeks, while walking activity remained unchanged for the controls. There were no significant reductions in blood pressure with walking in either low or high group. No significant changes were observed in variables associated with blood pressure including body composition, insulin, glucose, insulin/glucose ratio, or caloric intake. Also, there were no changes in depression, hostility, aggression, or self-esteeem scores with walking. There were also no significant differences in submaximal heart rate or blood pressure, however, the respiratory exchange ratio was significantly reduced in the low and high groups (p < 0.05), demonstrating a training adaptation. Women who responded favorably (decrease in systolic or diastolic blood pressure > 10 mm Hg) to the walking were characterized by having a greater adherence rate to the walking program, higher baseline levels of blood pressure, and a larger reduction in body mass in comparison to non-responders. It was concluded that a 12 week program meeting or exceeding the ACSM-CDC physical activity recommendations was ineffective in lowering blood pressure in postmenopausal women with borderline to mild hypertension. However, the strong associations between exercise adherence and blood pressure reduction as well as between weight loss and blood pressure decline suggest that these factors are critical to blood pressure reduction in postmenopausal hypertensive women.