Wednesday, June 19, 2013

Strength Training's Effect on Blood Pressure

What specific change in blood pressure can people expect to receive from exercise?

As discussed in the post "Walking as a Form of Exercise," aerobic exercise can immediately lower blood pressure. A 10-minute walk can lower systolic blood pressure 3-4 mmHg for a short time in healthy individuals. A 30-minute walk lowers blood pressure for an average of 22 hours. Essentially, if you took a 30-minute walk everyday, you can chronically lower your blood pressure.

Strength training's effect on blood pressure is a bit murky. Research isn't nearly as abundant. Also, for a long time, the perception was strength training is dangerous for blood pressure. Specifically, people believed strength training added extra resistance for blood flowing through the arteries and also increased the size of the heart's walls. Both of these changes increase blood pressure and ultimately increase the risk of a heart attack or stroke.

Research has shown these fears to be untrue. After analyzing nine studies assessing the effects of strength training on blood pressure, Belgian researchers found neither of the physiological changes occurred [1]. Here's what they did find: strength training lowers blood pressure.

The Magnitude of Change and Underlying Reasons

The nine studies analyzed included 341 people between the ages of 20 and 72 years old. The studies ranged from six to 26 weeks long. The average blood pressure reduction was 3.2/3.5 mmHg.

Those reductions have value but are not life-altering. However, these studies were mostly performed with healthy people with desired blood pressure numbers. In general, people with less room to improve will do just that: improve to a smaller degree. Men and women with hypertension are likely to see greater improvements.

A few weeks ago, I talked about the underlying reasons for high blood pressure often being the same as the underlying reasons for diabetes: insulin resistance, excess insulin in the blood, and high blood glucose. Strength training improves all three factors, which is why it might improve blood pressure, even when blood pressure already falls into a healthy range.

Taking Action to Improve Your Blood Pressure

In case you're curious, the average blood pressure improvement from aerobic exercise is essentially the same as strength training: 3/3.3 mmHg [2]. If you are worried about hypertension, I recommend a combination of strength training and aerobic exercise. Many of the strength training studies found blood pressure benefits with a minimal frequency of two workouts per week. In regards to aerobic exercise, intensity is not important, so walking will provide as much benefit as jogging. Frequency and duration are more important factors, so take longer walks, or go out frequently, even if just for 10 minutes.


Steve Parker, M.D. said...

Thanks for this post.

Yeah, those BP reductions are quite modest, but they're averages. I'm sure some people in the studies dropped their pressures as much as 10 points.

That lucky minority (10%?) might be able to avoid drug therapy for hypertension, while getting all the other benefits of exercise.


Dr. Sean Preuss said...

Hi Steve,

You're absolutely right: the average BP changes with diastolic and systolic ranged from about +2 to -16 mmHg in the various studies. Several individuals were likely able to prevent or drop BP medications, thanks to strength training.

Thanks for reading. I hope all is well with you.