Ask the Experts

Q. Can getting regular physical activity actually help lower my blood pressure and how so? Does it also do anything for my cholesterol?

A. Dr. Barry Franklin of the William Beaumont Hospital Heart Center says physical activity has shown to lower blood pressure, although we are not sure exactly how. One theory is that physical activity lowers the heart rate and this is what lowers blood pressure. Another theory is that physical activity reduces stress. Stress is tied in with the catecholamine hormones, epinephrine and norepinephrine, which are known to raise blood pressure. Lowering stress and consequently lowering catecholamines may lower blood pressure.

Physical activity can also reduce body weight and body fatness, and sometimes as body weight decreases, so does blood pressure. Regular physical activity may also have a direct effect on the vascular system, which ultimately results in decreased peripheral resistance. People with mild hypertension tend to get the most benefit on their blood pressure from exercise. Generally it’s lowered an average of 5–7 mm Hg after an exercise session.

My exercise prescription to optimally reduce blood pressure would involve frequency, intensity and time. Get endurance (aerobic) exercise most, and preferably all, days of the week at 40–60 percent of your capacity for an accumulated time of at least 30 minutes per day and complement this aerobic exercise with resistance training 2–3 days of the week.

As far as cholesterol goes, physical activity may be beneficial, but it only changes the levels modestly. It’s not the best way to lower cholesterol. Generally the favorable changes in cholesterol are from the reductions in body weight or fat stores that come from regular exercise, so it’s an indirect relationship. For exercise alone to increase your HDL, or “good” cholesterol, some studies suggest that you would need to walk or jog at least 10 miles every week.

Even though I recommend at least 30 minutes, and preferably 60 minutes of physical activity most days of the week, you shouldn’t let those time limits keep you from doing as much as you can. For example, if you’re currently doing nothing and you can manage 8–10 minutes of walking three days a week, that’s great. Something IS better than nothing! Do what you can. You’ll find that’s it’s pretty addictive, and if you can just get started, your body will help you add minutes. A body at rest tends to remain at rest. A body in motion tends to remain in motion. That’s just physics! Take the first step. Take action!

The same goes for losing weight. If you’re a 300-pound person and you think you can get to 280, work for that. Don’t overwhelm yourself. It’s self-defeating. Worry about getting to 180 only after you’ve had several 10 or 20 pound weight loss successes. The long and short of it is, do whatever you can. Don’t deny yourself the benefits of a little physical activity because you don’t think you can get a lot. Every minute counts, and remember, more fit people — whether they are thin, overweight or obese — have a lower mortality rate than less fit people of the same body habitus (physique). So even if you’re not losing weight, you’re adding quality and time to your life when you become more active.