Academic journal article Bulletin of the World Health Organization

Physical Exercise in the Management of Hypertension

Academic journal article Bulletin of the World Health Organization

Physical Exercise in the Management of Hypertension

Article excerpt

Physical activity is widely regarded as a protective factor against cardivascular diseases. Converserly, physical inactivity is considered to be a cardiovascular risk factor.

The relation between physical activity and blood pressure has been determined from epidemiological data and from various controlled studies in which normotnesive and hypertensive subjects underwent physical training.

Physical activity, physical fitness, and

blood pressure

Epidemiological studies

Various studies ahve analysed the relation between blood pressure and physical activity using data obtained from questionnaries and interviews with people at work or leisure or both. Other studies have used an exercise test to assess physical fitness or performance capacity; however, this is determined not only by physical activity and training but also by genetic factors [1]. The assessment of physical activity from responses to questionnaires and interviews bears only a poor relationship to measured physical fitness: some physically active people may appear unfit on testing and some physically inactive may appear fit. In general, the methods used to assess physical activity lack accuracy and differ widely between studies.

Several confounding variables may affect the relation between physical activity, physical fitness, and blood pressure. Some of these, such as age, weight, and obesity, can be accounted for in analyses; others, such as self-selection and genetic effects, cannot easily be controlled. Several large studies, involving more than 13500 subjects, and which allowed for age and anthropometric characteristics, have reported an inverse relation between blood pressure and either habitual physical activity [2-4] or measured physical fitness [5, 6]. Also, in a follow-up study of college alumni, Paffenberger et al. observed that vigorous exercise was inversely related to the later development of hypertension, especially in the obese [7].

Not all epidemiological studies support this view [8]; however, the low level of physical activity in Western societies may have hampered the detection of such a relation. Moreover, in studies that did find a significant association, the difference in blood pressure between the most and the least physically active subjects amounted to not more than 5 mmHg [5, 6]. Such a small reduction may have important consequences for the morbidity and mortality of populations, but is of no practical benefit to the individual.

Training studies

The effect of physical training on blood pressure has been assessed in many studies [9]. Only controlled studies are considered in this article, i.e., studies in which parallel nontraining control groups were followed ow which included a nontraining phase. It should be realized, however, that patients cannot be blinded to the treatment in training studies. Most studies used so-called "endurance" training) prolonged dynamic, predominantly isotonic, exercise of large muscle groups), for example, walking, running, cycling, swimming, and cross-country skiing. In this context, endurance does not imply extreme exertion, such as that experienced in a marathon race.

Studies of the effect of "static" or isometric training, which involves muscle contractions with limited or no movement of the subject, and is thus performed at relatively constant muscle length, have also been carried out; examples are weight-lifting and wrestling.

Endurance training. Data on the effect of endurance training on blood pressure have been reported for at least 29 study groups of normotensive and hypertensive subjects, mostly men, of average age range 16-70 years. The duration of the training was 1-8 months, carried out mostly in three weekly sessions of 30-120 minuts each. The intensity of the training varied from 50% to 90% of maximal exercise capacity. The training programmes produced increases in exercise capacity of 6% to 38%, and the subject's weight usually remained unchanged. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.