Exercise and Blood Pressure: 8 Questions?>

Exercise and Blood Pressure: 8 Questions

by Wellness Letter  

If you’ve found out you have hyperten­sion (blood pressure over 130/80), you were probably told that life­style measures are the first step in getting your blood pressure under control, before turning to medication. Besides losing weight (if you are overweight), improving your diet (notably cutting down on sodium), and quitting smoking (if you smoke), a stan­dard recommendation is to start exercising (if you aren’t already). The same steps are advised if you have mildly elevated blood pressure below the hypertension range.

But what’s the best way to exercise to help control blood pressure? How much do you need to do to get a significant ben­efit, and do you have to take any precau­tions? Here are some answers.

Is there a recommended exercise regimen for hypertension?

Exact recommendations by expert groups differ somewhat, but the general consensus is that people with hypertension should do moderate-to-vigorous aerobic (cardio) exercise such as running, brisk walking, or cycling at least several times a week. Strength training can be done instead of some of these sessions, though preferably in addition to them. People with hyperten­sion should start at low intensity and work up to moderate.

How much can exercise reduce blood pressure?

It can vary from person to person, depend­ing on many factors. Initially, systolicblood pressure (the first number) rises during the exertion of exercise, but it should return to normal and then drop even lower after a short period of rest. Typically, a bout of exercise results in a reduction in systolic blood pressure of 5 to 7 points, which may last for a number of hours. The effect on diastolic pressure (the second number) is generally smaller and more variable. This post-exercise drop in blood pressure is thought to result from a dilation of blood vessels in the body’s extremities.

Exercise programs may reduce bloodpressure in people with hypertension as much as first-line medication does, accord­ing to an analysis in the British Journal of Sports Medicine in 2018. It looked at 391 clinical trials, half focusing on the effects of exercise in mostly non-hypertensive people, the other half on the effects of medication in people with hypertension. When the findings from the exercise trials were limited to results for participants with baseline hypertension, the reduction in sys­tolic blood pressure was the same as seen in the drug trials—about 9 points.

Do you have to exercise for at least 30 minutes per session, or can you do shorter bouts?

Recent research has found that accumulating short bouts of exercise each day can be just as beneficial as longer bouts, or even more so. This is good news for people who don’t have time for longer workouts. For instance, in a small 2012 study in Medicine & Science in Sports & Exercise, young people with mildly elevated blood pressure walked briskly three times a day for 10 minutes, and the next day they walked briskly once for 30 minutes. Their blood pressure was monitored con­tinuously both days. The divided schedule produced slightly lower 24-hour readings, as well as fewer daily spikes in blood pressure.

How much can strength training help control blood pressure?

Doctors used to warn people with hyper­tension against it, since strenuous lifting can cause a temporary spike in blood pres­sure. But in recent years, research has found that strength training can be as effective as aerobic exercise at lowering blood pressure. The benefit comes from standard (some­times called dynamic) resistance training, in which muscles and joints move against resistance. Thus, the American College of Sports Medicine and the American Heart Association now recommend that people with hypertension do both aerobic exercise and moderate dynamic resistance training.

An analysis of 64 studies testing dynamic resistance training for people with hyperten­sion, published in the Journal of the American Heart Association in 2016, found that it reduced blood pressure (both systolic and diastolic) by about 6 points in people with hypertension and 3 points in those with pre­hypertension. Resistance training “can elicit blood pressure reductions that are compa­rable to, and in some cases greater than, those that have been previously reported with aerobic exercise,” the study concluded.

What about handgrip exercise?

A review paper from the American Heart Association, published in Hypertension in 2013, concluded that isometric handgrip exercise, done regularly, can produce sig­nificant reductions in blood pressure. A 2017 systematic review in the journal Sports reached similar conclusions.

If you have hypertension, there’s no harm in trying handgrip exercise as an adjunct therapy—in addition to aerobic exercise. You can experiment with a basic, inexpensive spring-loaded handgrip device, squeezing it at moderate intensity for a couple of minutes several times a day. Another option is to squeeze a rubber, foam, or tennis ball. There’s also a computerized handgrip device called Zona Plus ($600), designed for blood pressure control.

Is there a best time of day to exer­cise for lowering blood pressure?

Studies comparing morning and evening exercise for people with hypertension have produced inconsistent results, though most research gives evening exercise a slight edge—maybe. A Brazilian study published in 2019 in Medicine & Science in Sports & Exercise included sedentary men with hypertension (average age 50, on medication) who did stationary cycling at moderate intensity in either the morn­ing or evening for 45 minutes three times a week for 10 weeks. Blood pressure was measured shortly after exercise and by 24-hour ambulatory testing.

Systolic blood pressure dropped significantly only when measured after evening exercise; diastolic blood pressure dropped only in ambula­tory testing done after evening exercise. The average reductions were 8 points sys­tolic and 3 points diastolic. Still, the best time of the day to exercise is the time that works best for you, your body clock, and your schedule.

Should people with hypertension be medically evaluated before beginning to exercise?

A medical clearance is warranted before starting exercise if you have uncontrolled hypertension; have cardiovascular, meta­bolic, or kidney disease or symptoms of them, such as shortness of breath or dizzi­ness; or have risk factors for cardiovascular disease, such as obesity. If you are already exercising and have any such symptoms, stop and talk with your doctor, who may suggest an exercise stress test. Exercise is contraindicated for anyone with severe uncontrolled hypertension—notably, rest­ing systolic blood pressure above 180 or diastolic pressure above 110—until medi­cation gets it under control.

Can anti-hypertensive drugs affect exercise?

Some drugs used to treat hypertension may cause problems when exercising. For instance, beta blockers (such as metoprolol) can make aerobic exercise difficult because they make it hard to raise heart rate to the standard training range. And beta block­ers and diuretics (such as hydrochlorothia­zide) can impair the body’s heat regulation. Whatever anti-hypertensive drug you are taking, if you experience any symptoms when exercising, consult your doctor, who may adjust your medication or advise alter­ations in your exercise regimen.

This article first appeared in the UC Berkeley Wellness Letter.