Kerry Stewart, director of Clinical and Research Exercise Physiology at Johns Hopkins School of Medicine, says that keeping your muscles in a contracted position requires you to “work very hard.”
“Maybe that’s one of the reasons why it provides benefits,” he adds.
Why isometric exercise is better for blood pressure?
When you do any type of exercise, your blood pressure temporarily increases because your heart pumps harder, moving blood through your arteries with more force. If you exercise repeatedly, your heart becomes stronger, so it can pump blood with less effort, and that can help lower your resting blood pressure.
Isometric exercise may offer an additional benefit because when you maintain a muscle contraction, you restrict blood flow to those muscles, Stewart says. Then, when you stop doing the exercise, “you get a big surge of blood” to the area, he explains. That extra blood flow stimulates the lining of your arteries to produce nitric oxide, which causes blood vessels to relax and widen, which ultimately lowers blood pressure, he says.
Stewart says she wouldn’t recommend doing just isometric exercises, but rather adding them to a fitness program that also includes aerobic and resistance exercises.
“Cross-training appears to provide not only a benefit for blood pressure control, but also for overall health,” he says. “That’s where you get the most benefit possible.”
How to start isometric exercise
If you have been diagnosed with high blood pressure or other cardiovascular problems, talk to your healthcare provider before starting an exercise program.
The study in BJSM found that just three sessions per week of isometric exercise can lead to a significant reduction in blood pressure. The study found that doing wall squats, for example, reduced systolic blood pressure by 10 mmHg and diastolic pressure by 5 mmHg.
The isometric exercise programs analyzed in the study commonly had participants perform each exercise four times, with a rest in between, holding the position for up to two minutes.
Dobrosielski, who works with older adults, says that if you haven’t done isometric exercises before, holding a position for 20 to 30 seconds is a good starting point. It’s normal for your body to start shaking as your muscles get tired, he says. “You can gradually build up to longer,” he says.