An analysis of data from nearly 15,000 people revealed that running, biking, climbing stairs or brisk walking for just those few minutes can have a positive effect on blood pressure. Increasing activity up to 20 minutes can reduce the risk of heart disease by a significant amount, according to the report published Wednesday in Circulation.

"Exercise is the most important thing favorably associated with blood pressure," Mark Hamer, a professor in sport and exercise medicine at University College London, said in a Zoom interview.

People with high blood pressure have a higher risk for heart disease and stroke, the leading causes of death in the U.S. In 2022, high blood pressure was a primary or contributing cause of 685,875 deaths, according to the Centers for Disease Control and Prevention.

Nearly half of all Americans have high blood pressure, which is defined as a systolic blood pressure (the upper number) of greater than 130 or a diastolic blood pressure (the lower number) greater than 80.

Adults should get 150 minutes of moderate to vigorous physical activity per week, most guidelines recommend.

To look at how much of an effect exercise might have on blood pressure, Hamer and his colleagues combined data from six earlier studies that required participants to wear movement trackers on their thighs 24-hours a day.

The 14,761 participants had an average age of 54 and were almost evenly divided between male and female (53% women).

On average, participants spent seven hours a day sleeping, 10 hours in sedentary behaviors such as sitting, three hours standing, one hour slow-walking, one hour fast-walking and 16 minutes in vigorous exercise.

The researchers found that replacing any less active behavior with five minutes of exercise could lower systolic blood pressure by 0.68 points and diastolic blood pressure by 0.54 points. When exercise time was 15 minutes longer, the reduction was bigger.

An estimated two point improvement in systolic blood pressure was observed when 20 minutes of vigorous exercise replaced, for example, 21 minutes of sedentary time or 26 minutes of slow-walking. Previous research found that a decrease of two points in systolic blood pressure could result in a 7% to 10% reduction in heart disease and stroke death, the researchers note.

The new study "adds more evidence supporting the idea that even a small amount of movement can have a meaningful effect on cardiovascular health," said Dr. Arun Manmadhan, an assistant professor of medicine at the Columbia University Vagelos College of Physicians and Surgeons in New York City.

The idea of vigorous exercise can be daunting to people who are out of condition, Manmadhan said. "This study tells us that a starting point of five to 10 minutes a day can help," he added. "The blood pressure improvement from five minutes alone is not that meaningful -- it's less than one point. But you can ramp up from that to the point where there is a clinical improvement to your cardiovascular risk profile."

There are lots of barriers to getting started, said Dr. Matthew Tomey, a cardiologist at the Mount Sinai Fuster Heart Hospital in New York City, who was not involved with the research. "Some people feel like they are too busy," he added. "Papers like this point out that it doesn't have to take up a huge amount of time. Depending on what you're doing you may need little or no equipment."

The chief takeaway from this study is that every bit of exercise is important, said Dr. Sean P. Heffron, an assistant professor of medicine and director of cardiovascular fitness and nutrition at New York University Langone Medical Health. Heffron was not part of the new study.

"I try to encourage people to do things they enjoy, such as hiking," Heffron said, adding that the new findings might help people who are out of condition to start working out.

Having a step tracker, such as the ones often included in smart phones, can help people self-monitor how much exercise they are getting, said Dr. Evan Brittain a professor of medicine in the division of cardiology at the Vanderbilt University Medical Center in Nashville.

"We used to think if you didn't go for 20 or 30 minutes at a time, it wasn't enough," said Brittain, who was not part of the research. "There's a lot of data now showing that short bursts of activity work."