Q. I have high blood pressure and I have been on maintenance medication for the past seven years. So far, my blood pressure is under control and I have no other health concerns. I heard on the radio that exercise can lower one’s blood pressure. My question is: can exercise treat hypertension? I am sedentary. If I exercise, will I be able to bring down my blood pressure to normal so that I need not take medicines anymore?

– jordanlv@gmail.com

A. Existing evidence shows an inverse relationship between blood pressure and exercise, which in this context refers to progressive training programs that are undertaken on a regular basis (four to seven times a week). Evidently, up to a certain degree, the more a person exercises the lower his/her blood pressure is.

Exercise training can be categorized, albeit simplistically, into two types: dynamic and static. Dynamic exercise is essentially synonymous with aerobic or isotonic exercise. It involves repetitive activities by large muscle groups performed with little resistance to movement like jogging and cycling. Static or isometric exercise on the other hand, involves sustained activities that change muscle tension but without altering muscle length. It is contraction of the muscles against resistance, where resistance comes from free weights, weight machines, one’s own body's weight, etc.

When performed regularly, either of the two types of exercise reduces blood pressure in normal and hypertensive people. However, during the time the person is doing his exercise routine, both types elevate the blood pressure with static exercise raising the mean blood pressure significantly higher than dynamic exercise. This phenomenon is the reason why dynamic exercise is presumed to be safer of the two forms and hence, is the more popular and dominant component of many long term exercise programs.

Clinical trials among hypertensive subjects using mostly dynamic programs, e.g., 10 minutes warm-up followed by five minutes of cycling that slowly increases in duration over several months, showed significant decrease in blood pressure readings. This fall in blood pressure allowed for a lowering of the maintenance dose of anti-hypertensive drugs for most of the subjects. The positive effect is appreciated as early as three months after initiation of training and disappears three months after cessation of the exercise program.

All the above facts notwithstanding, exercise alone is probably not adequate to treat even mild hypertension. Thus, exercise is best viewed as merely an adjunctive measure in the treatment of the condition. The other modalities of treatment which include dietary modification (i.e., low-salt, low-fat diet), reduction of alcohol intake, cessation of smoking, maintenance of ideal body weight, stress management, control of chronic conditions that aggravate hypertension such as high cholesterol, diabetes, kidney disease and sleep apnea, and intake of maintenance anti-hypertensive medications, should not be neglected.

By the way, healthy people can immediately undertake a moderate exercise program without any supervision, but the habitually sedentary and those with known chronic illnesses like heart disease and diabetes should exercise only with medical supervision, because, for these people, exercise can trigger a heart attack.

In your particular case, inasmuch as you do not have any other chronic illness while your hypertension is under control, you can immediately start a supervised progressive dynamic exercise program. Exercise alone will probably be not enough to bring your blood pressure down to normal but it might enable you to reduce the dosage of your maintenance drugs. Remember too that exercise has numerous other health benefits including prevention of atherosclerosis (the underlying cause of most heart attacks and strokes), and enhancement of mood, self-esteem and sense of well-being.

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