EFFECT OF EXERCISE TRAINING ON AMBULATORY BLOOD-PRESSURE

A possible hypotensive action of regular endurance exercise in normote nsive sedentary subjects still remains a matter of debate. This is par tly caused by the fact that the anticipated fall in resting blood pres sure is rather small and fluctuations in blood pressure during the day can be large. The benefits of ambulatory blood pressure monitoring (A BP) originate to a great deal from the fact that the repeatability on different occasions of the ambulatory blood pressure average is improv ed by the greater number of readings. In this context we evaluated the effect of moderate exercise training in 19 sedentary male subjects, a ged 22 to 44 years, with normal or slightly elevated blood pressure. T hey 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 mi n at 75 % VO(2)max. ABP was measured with a Spacelabs 90207 monitor an d cardiac output at rest with echo-Doppler. Training increased VO(2)ma x from 3.13 +/- 0.09 to 3.40 +/- 0.081/min (p<0.01). Resting heart rat e decreased from 60 +/- 2 to 57 +/- 2 bpm (p<0.05). Resting blood pres sure was unchanged after training. Resting stroke volume increased fro m 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 me ans of systolic BP (S: 125 +/- 4; T: 125 +/- 4 mmHg), diastolic BP (S: 79 +/- 3; T: 78 +/- 3 mmHg) and HR (S: 73 +/- 3; T: 72 +/- 4 bpm) did not differ between the two cross-over periods. In conclusion, moderat e physical training for six weeks does not lower ambulatory blood pres sure, blood pressure at rest and during exercise in normotensive seden tary male subjects; this despite clear cardiac adaptations and a reduc tion in systemic vascular resistance.