Long-term aerobic exercise controls high blood pressure as effectively as antihypertensive drugs. That’s the encouraging conclusion of an important new study from Germany – the first to investigate long-term exercise as a single therapy for hypertension.
Ten newly-diagnosed hypertensive middle-aged men, who had previously led sedentary lifestyles, were assigned to a three-year aerobic exercise programme comprising two supervised training sessions per week, starting with walking and intermittent slow jogging and building to a maximum of about 60 minutes of long-distance running.
Blood pressure was measured at rest and during cycle ergometry at the beginning of the study period, and then under identical conditions six months, 1.5 years and three years after the onset of training.
The results speak for themselves: after six months of training, pressures during exercise were significantly lower (170/100mmHg compared with 184/107), although BP at rest had not fallen significantly; after 1.5 years of training, there was a significant reduction in resting BP (from 139/96 to 133/91) and after three years resting BP had fallen still further to 130/87, while pressure during exercise had fallen to 167/92.
In total, resting systolic blood pressure (the higher of the two measurements) decreased by 6.5% and diastolic by 9.4% over the study period. The corresponding percentage falls for BP during exercise were 9.2% and 14%. According to the authors, this effect was ‘more intensive than what we found using various antihypertensive medications’.
They regard the large reductions in BP during exercise as particularly encouraging, since BP during exercise has been found to correlate more closely with organ damage than resting pressures.
Other studies examining the effects of aerobic exercise over shorter study periods have noted only mild reductions in resting BP. And the German researchers believe that the duration of exercise intervention may be the most important factor in reducing BP.
They are in no doubt that it is the exercise, rather than any associated factor, that was responsible for the dramatic falls in blood pressure. Weight loss is often recommended as a route to healthier blood pressure, but could not have been a factor in this study since the subjects experienced no significant changes in body weight during the training period.
They conclude: ‘The reduction in BP in hypertensive patients seen after long-term aerobic training therefore implies that exercise has a beneficial effect in the management of hypertension and that pharmacological treatment can be deferred or probably prevented in hypertensive subjects who regularly engage in aerobic sports activities.
‘Regular exercise implies a beneficial effect in the management of hypertension that is comparable to that of drug therapy. An additional advantage of physical activity is other healthy “side effects” that are known to influence cardiovascular risk. The disadvantage of taking drugs daily with its risk of side effects and costs may be avoided, and patients feel that they can affect their wellbeing and are not victims of disease.’
Med Sci Sports Exerc, vol 36, no 1, pp4-8, 2004