Exercise is a heart-healthy activity! How do we know this? Studies show that people who work out, especially aerobic exercise, are at a lower risk of developing cardiovascular disease and stroke. One way exercise benefits heart and blood vessel health is by lowering blood pressure, the force within the wall of arteries, the vessels that carry blood to tissues in the body.
Over the long term, aerobic exercise has a significant impact on blood pressure. To support this, a meta-analysis, an analysis of multiple studies, published in the Annals of Internal Medicine showed that regular exercise lowers systolic blood pressure by 3.84 points and diastolic blood pressure by 2.58 points on average. It lowers blood pressure in men and women with and without hypertension. Therefore, exercise is good “medicine” for a healthy heart! How does blood pressure and heart activity change when you train?
The Short-Term Effects of Exercise on Blood Pressure and Heart Rate
During aerobic exercise, blood pressure, particularly systolic blood pressure, goes up. This is a normal response to any kind of stress on the body, including exercise. Systolic blood pressure, the upper number, is the force in the walls of arteries when the heart is pumping. It makes sense that blood pressure would climb temporarily during exercise since energy demands are higher and the heart must pump harder and faster to deliver oxygen to tissues. Plus, the sympathetic or “fight or flight” component of the nervous system is activated, and this causes a rise in blood pressure.
It’s normal for systolic blood pressure to rise as high as 220 mmHg during an additional exercise session due to the additional demands exercise places on the heart. If blood pressure climbs higher than this during exercise, it could indicate a possible heart problem and should be checked by a physician.
After a workout, systolic blood pressure gradually comes down to its baseline value. People with hypertension sometimes develop larger spikes in systolic blood pressure. If you’re out of shape and unaccustomed to exercising, systolic blood pressure may rise quickly even with minimal activity. As you become more aerobically conditioned, the rise is not as fast or sharp. Certain blood pressure medications, particularly beta-blockers, can interfere with the normal rise in heart rate and blood pressure.
Heart rate also changes during exercise. As mentioned above, heart rate increases proportionally to the demands of exercise. For example, your heart rate will rise more during a bout of high-intensity exercise than it does for a leisurely stroll in the park. In fact, your heart rate is a measure of how hard you’re working. To do this, determine your maximal heart rate using one of the available formulas. One formula is:
220 – age = maximal heart rate
Now, compare your heart rate during exercise to your maximal heart rate. You can do this by taking your pulse for 10 seconds and multiplying by 6. Moderate-intensity exercise would correspond to a heart rate of 50 to 70% of maximal heart rate. Above that would be high intensity.
The Long-Term Effects of Exercise on Blood Pressure
Over time, aerobic exercise can lower systolic and diastolic blood pressure. One way it does this is through adaptations that make the heart a more efficient pump. You may have noticed that as you become more physically fit, your resting heart rate slows. That’s because your heart becomes more efficient and it doesn’t have to beat as many times per minute to deliver blood and oxygen to tissues at rest. A more efficient cardiovascular system reduces the force on the walls of arteries, the blood vessels that carry blood and oxygen to tissues. This leads to a drop in blood pressure.
Aerobic exercise also improves endothelial function. The endothelium is a thin layer of cells that produce factors that cause arteries to open up or tighten. With regular aerobic activity, endothelial cells produce more factors that cause the arteries to relax or expand. In turn, this leads to a reduction in blood pressure. The endothelium also produces factors that impact blood clotting. Improvements in endothelial function are another way exercise reduces the risk of cardiovascular disease and stroke.
What about long-term effects on heart rate? As mentioned, when you exercise aerobically over several weeks or months, your heart becomes more efficient at pumping blood and oxygen. Therefore, your resting heart rate will slow. If your heart is otherwise healthy, a slow resting heart rate is often a sign of greater aerobic fitness. Endurance athletes frequently have slow resting heart rates, especially athletes that run or cycle long distances.
What about Resistance Training?
Working your body against resistance by lifting weights or doing bodyweight exercises can lead to a temporary rise in blood pressure. In some people, the increase in blood pressure can be substantial. Holding your breath while lifting or using very heavy weights can boost blood pressure even more. That’s why it’s important to check with a health care professional before weight training with hypertension.
However, longer-term research suggests that resistance training may lower blood pressure too. In fact, a meta-analysis published in the journal Hypertension showed resistance training modestly reduced systolic and diastolic blood pressure readings in healthy adults. The degree of blood pressure lowering in response to resistance training was 2%, on average, for systolic blood pressure and 4% for diastolic blood pressure. We think of aerobic exercise as being heart healthy and weight training as a way to develop strength. However, weight training may have heart health benefits as well.
Conclusion
Exercise temporarily raises systolic blood pressure, but over time, the adaptations associated with aerobic training can modestly reduce systolic and diastolic blood pressure. Although exercise is a heart-healthy activity, talk to your physician if you have high blood pressure, heart problems, or any other medical problem before starting an exercise program.
References:
Hypertension. 2000 Mar;35(3):838-43.
Arq Bras Cardiol. 2016 May; 106(5): 422-433.
NewScientist.com. “Exercise may lower high blood pressure as much as medication”