Exercise: the right prescription for hypertension, regular aerobic exercise is a key to lowering your blood pressure.

Can regular exercise training prevent hypertension from developing or help treat it once acquired? The answer to both of these questions is yes, with researchers now concluding that exercise is a powerful weapon against high blood pressure.

In regard to prevention, several major studies have shown that active, fit individuals have a 20 to 50 percent decreased risk of developing hypertension compared to their more sedentary peers. In a six- to ten-year study of 15,000 Harvard male alumni, for example, those who engaged in sports and physical activity were 35 percent less likely of becoming hypertensive than those who were basically inactive.

When a person walks briskly, cycles, jogs, swims, or engages in other aerobic activities, the blood pressure rises. For 30 to 120 minutes afterward, however, the blood pressure falls below normal. Over time, as the exercise is repeated, there is growing evidence that a long-lasting reduction in resting blood pressure can be experienced.

The American College of Sports Medicine (ACSM) in a recent position stand on exercise and hypertension concluded that people with mild hypertension can expect both systolic and diastolic blood pressure to fall an average of 10 mm. Hg in response to regular aerobic exercise.

Your Body Responds Quickly

How quickly does the resting blood pressure fall? Most studies show that exercise training acts quickly to improve blood pressure among hypertensives, with most of the effect taking place within the first few weeks.

Dr. Michael Kelemen, for example, reported in the Journal of the American Medical Association results from a study in which hypertensives exercised aerobically three times a week for 10 weeks while taking either a diuretic or beta-blocker (hypertensive drugs), or a placebo (a pill with no drug in it). Exercise alone without drugs resulted in an impressive 8 mm. Hg drop in the diastolic blood pressure, with drug therapy adding some extra benefit. Interestingly, most of the improvement in blood pressure occurred during the first week, with some additional progress up to four weeks.

Soon after stopping exercise training, however, blood pressure quickly returns to its initial untrained level. In other words, the blood pressure-lowering effect of exercise training depends on a regular schedule of activity.

The American College of Sports Medicine has established that effective lowering of blood pressure can be achieved with moderate intensity exercise conducted three to five times a week for 20 to 60 minutes per session. In fact, moderate-intensity exercise such as brisk walking may have an even greater blood pressure-lowering effect than higher intensity training (like running).

ACSM does not recommend weight training as the only form of exercise for hypertensives. Weight training does not appear to be as effective in lowering blood pressure as aerobic exercise. Lifting weights, however, is an excellent way to increase muscular strength, and is recommended for overall physical fitness.

How does regular exercise lower the blood pressure? Although researchers are still studying the causes, exercise does appear to relax the blood vessels, decrease the levels of certain hormones, and improve kidney function.

Prevention Starts With You

Although high blood pressure is a common ailment, especially among the elderly in the United States, there are some countries where hypertension is rare. In these countries, mostly non-Western in lifestyle, people are physically active, eat plenty of fruits and vegetables, and keep salt and alcohol intake low. So it does not appear that hypertension is the inevitable consequence of old age.

What can you do? The National institutes of Health urges that you support the start of a national campaign to promote regular exercise, abstinence or moderation in alcohol intake, and foods in the supermarkets that are lower in sodium and calories and high in potassium. "Given the high prevalence of a sedentary lifestyle among U.S. residents," reiterates the NIH, "performance of moderate intensity, low resistance, dynamic exercise such as walking, cycling, and gardening could play a valuable role in the prevention of hypertension."

RELATED ARTICLE: Got A Minute For Your Heatlh?

Celery

Many of us want to know about foods that can improve our health, and scientists continue to come out with interesting findings. For instance, have you thought about celery lately? Even though it's somewhat high in sodium compared to other vegetables, it also contains a chemical that appears to lower blood pressure.

Inspired by an ancient Asian treatment for hypertention, researchers at the University of Chicago fed rats an amount of this compound that you'd find in four stalks of celery. The substance relaxed blood vessels, resulting in lowered pressure. Of course that's not to say you should eat celery if you have high blood pressure. You should see a doctor and take your prescribed medication. But if your blood pressure is normal, and you want something to munch on, a few stalks of celery won't hurt.

Listen to Got a Minute for Your Health? on many local radio stations.

Jan W. Kuzma, Ph.D., is president of Sentinel Research Services and former director of research at the School of Public Health, Loma Linda University, Loma Linda, California.

David C. Nieman is Professor of health and exercise science at Appalachian State University, Boone, North Carolina.