Effects of walking and other exercise programs upon blood pressure in normal subjects.

OBJECTIVE

Rational use of non-pharmacological therapy for elevated blood pressure requires some knowledge of dose-effect relationships to optimise regimens. We investigated the effects on blood pressure of: one hour of walking at 50% of predetermined maximal work capacity (Wmax); 15 minutes of cycling at 80%-90% of Wmax (high-intensity cycling; HIC)--each performed five days per week; and three 30-minute cycling sessions per week at 65%-70% of Wmax (moderate-intensity cycling; MIC) which we have previously found lowers blood pressure in both normotensive and hypertensive people.

DESIGN

The three exercise interventions and a period of normal sedentary activity were performed for four weeks each, by 14 normotensive volunteers (seven male, seven female) in a randomised 4 x 4 Latin-square design.

RESULTS

MIC produced the greatest blood pressure reduction relative to the period of normal sedentary activity--mean 5/3 mmHg; standard error of the difference (SE-diff) 2/1 mmHg; P < 0.05 in the supine position, and 4/5 mmHg; SE-diff 2/2 mmHg; P < 0.05 standing. Walking induced smaller blood pressure reductions--3/2 mmHg; SE-diff, 2/1 mmHg (P < 0.05 for systolic pressure), and 2/1 mmHg; SE-diff, 2/2 mmHg for the supine and standing positions, respectively. The HIC did not change blood pressure. Heart rate reduction with training was proportional to exercise intensity. Cardiac output, body weight, 24-hour urinary sodium excretion, cholesterol and triglyceride levels did not alter with any of the interventions.

CONCLUSIONS

Effects of exercise on blood pressure vary according to the intensity and duration of training bouts. Moderate exercise levels may be optimal, but walking is also effective.