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.