Effect of Exercise Training on Ambulatory Blood Pressure

Abstract

A possible hypotensive action of regular endurance exercise in normotensive sedentary subjects still remains a matter of debate. This is partly caused by the fact that the anticipated fall in resting blood pressure is rather small and fluctuations in blood pressure during the day can be large. The benefits of ambulatory blood pressure monitoring (ABP) originate to a great deal from the fact that the repeatability on different occasions of the ambulatory blood pressure average is improved by the greater number of readings. In this context we evaluated the effect of moderate exercise training in 19 sedentary male subjects, aged 22 to 44 years, with normal or slightly elevated blood pressure. They entered a randomized cross-over study. Measurements were performed before the study, after 6 weeks of sedentary life style (S) and after 6 weeks of training (T) on a cycle ergometer 3 times a week for 45 min at 75% V̇O₂max. ABP was measured with a Spacelabs 90207 monitor and cardiac output at rest with echo-Doppler. Training increased V̇O₂max from 3.13±0.09 to 3.4010.081/min (p < 0.01). Resting heart rate decreased from 60±2 to 57±2 bpm (p < 0.05). Resting blood pressure was unchanged after training. Resting stroke volume increased from 82±3 to 89+3 ml (p < 0.02). Systemic vascular resistance index was significantly decreased due to conditioning (p < 0.05). The 24-h means of systolic BP (S: 125±4; T: 125±4mmHg), diastolic BP (S: 79±3; T: 78±3 mmHg) and HR (S: 73±3; T: 72±4bpm) did not differ between the two cross-over periods. In conclusion, moderate physical training for six weeks does not lower ambulatory blood pressure, blood pressure at rest and during exercise in normotensive sedentary male subjects; this despite clear cardiac adaptations and a reduction in systemic vascular resistance.

Key words

Exercise training - blood pressure - ambulatory monitoring