When it comes to lowering blood pressure, studies have typically shown that aerobic or cardio exercises are best.
Now, new research suggests another type of physical activity is worth including as an effective tool to prevent and treat hypertension, or high blood pressure.
Exercises that engage muscles without movement — such as wall squats and planks — may be best for lowering blood pressure, according to a large study published Tuesday in the British Journal of Sports Medicine.
This type of training is known as isometric, or static, exercise, according to the Mayo Clinic. Isometric muscle action happens when muscles contract but do not visibly change length, and the joints involved don’t move, facilitating stability of the body.
Isometric exercises can be done with weights or without, just relying on the body’s own weight.
“Overall, isometric exercise training is the most effective mode in reducing both systolic and diastolic blood pressure,” said study coauthor Dr. Jamie O’Driscoll in a news release. He is a reader in cardiovascular physiology at Canterbury Christ Church University’s School of Psychology and Life Sciences in England.
“These findings provide a comprehensive data-driven framework to support the development of new exercise guideline recommendations for the prevention and treatment of arterial hypertension.”
BEST EXERCISE FOR BLOOD PRESSURE
Existing guidelines on exercise for blood pressure management — which emphasize aerobic or cardio exercises such as running or cycling — are effective but also based on old research that excludes more recently adopted exercise protocols such as high-intensity interval training and isometric training, the authors said.
The researchers felt the guidelines were outdated and in need of review, so they looked into randomized controlled trials that had reported the effects of exercise interventions, lasting two or more weeks, on systolic and/or diastolic blood pressure between 1990 and February 2023.
Systolic blood pressure measures the maximum pressure in the arteries as the heart contracts and relaxes, while diastolic blood pressure denotes what the arterial pressure is when the heart rests between beats, according to the US Centers for Disease Control and Prevention.
The authors defined healthy resting blood pressure as a reading below 130 over 85 millimetres of mercury — a measurement of pressure known as mmHg — pre-high blood pressure as ranging from 130/85 mmHg to 139/89 mmHG, and high blood pressure as 140/90 mmHG or greater. The top numbers of these figures are the systolic pressure; the bottom numbers are diastolic pressure.
From a review of 270 trials with 15,827 participants — which is known as a meta-analysis — the authors found that among HIIT, isometric exercise, aerobic exercise, dynamic resistance training and a combination of the latter two, isometric exercise led to the greatest reductions in blood pressure.
“The reductions in blood pressure after aerobic exercise training amounted to 4.49/2.53 mmHg; 4.55/3.04 mmHg after dynamic resistance training; 6.04/2.54 mmHg after combined training; 4.08/2.50 mmHg after HIIT; and 8.24/4 mmHg after isometric exercise training,” according to a news release.
Performing wall squats (isometric exercise) was most effective for reducing systolic pressure, and running (aerobic exercise) was most beneficial for decreasing diastolic pressure, but isometric exercise overall was best for lowering both pressure elements.
“It’s encouraging to see other forms of exercise explored in this research as we know that those who take on exercise they enjoy tend to carry on for longer, which is key in maintaining lower blood pressure,” said Joanne Whitmore, senior cardiac nurse at the British Heart Foundation, via email. Whitmore wasn’t involved in the study.
“However, it’s important to note that there are other lifestyle changes as well as exercise that can benefit your blood pressure,” she added. “These include keeping to a healthy weight, eating a balanced diet, cutting down on salt, not drinking too much alcohol and ensuring that you continue to take any prescribed medication.”
More research is needed to determine exactly why isometric exercises might be better for lowering blood pressure than other types of training, the authors said.
DOING ISOMETRIC EXERCISES
The authors said their findings should inform future guidelines about exercise for blood pressure.
Guidelines by the World Health Organization say people should do 150 minutes of moderate-intensity exercise weekly, which includes two strength-based training sessions.
“This research fits very nicely into those guidelines,” said Jim Pate, senior exercise physiologist at Marylebone Health Group in London, who wasn’t involved in the study.
You can do a wall squat or sit by standing with your back flat against a wall, then walking your feet about 1 1/2 feet (0.5 metre) out from the wall, with your feet shoulder-width apart, according to the Arthritis Foundation. With your back flat against the wall and your abs tight, inhale and then exhale as you squat as low as you can comfortably go without your butt going lower than your knees. Remain squatting until you feel pain, then inhale as you stand, pushing up from your heels. The Arthritis Foundation recommends doing 10 wall squats three times weekly.
Isometric training programs usually involve four two-minute contractions, separated by one- to four-minute rest intervals, done three times per week, according to the study.
If you have a heart condition, talk with your doctor about the best exercise for you, Whitmore said.
“People with health conditions should not be afraid to exercise in safe ways,” Pate said via email. “But seeking a professional who has experience with clinical exercise, like a sport and exercise medicine doctor, physiotherapist or clinical exercise physiologist, can help provide the structure and reassurance to make it achievable.”