THE EFFECT OF EXERCISE EPISODE DURATION ON BLOOD-PRESSURE

Objective: To investigate the effect on blood pressure for 10-min comp ared with 40-min episodes of physical activity for 4 days. Design and methods: The design used a randomized crossover trial of two exercise episode durations, involving 17 subjects, which were performed in a un iversity setting. The intervention was exercise on a stationary bicycl e for four consecutive days, at 50% of maximal oxygen uptake (determin ed by heart rate), for episode durations of 10 or 40 min. A rest perio d of 10 days followed before exercise for the alternative duration was performed. The main outcome measure was blinded assessment of blood p ressure 24 h after the last exercise episode.Results: Significant redu ctions were found in systolic and diastolic blood pressure after 4 day s of 40 min but not after 4 days of 10 min stationary cycling. The red uction in blood pressure was significant for both systolic and diastol ic blood pressure for 4 days of 40 min of exercise episodes. Conclusio n: Exercise of moderate intensity on a stationary bicycle for 10 min f or 4 days is not effective in lowering blood pressure in comparison wi th the same exercise for 40 min for 4 days. The experimental design em ployed in the present study has potential for monitoring the effects o f exercise on blood pressure.