Standing desks are not the answer to lowering blood pressure, clinical studies show

Alternating between sitting and standing at work reduces sedentary behavior but has no effect on lowering blood pressure, according to a study led by a West Virginia University epidemiologist. Researchers also found that standing too much while at work can have negative effects on cardiovascular health.

In a clinical trial, researchers expected to find that people with hypertension could lower their blood pressure with a behavioral intervention, including a sit-stand desk to reduce sitting.

“People reduced their sedentary behavior by more than an hour a day by standing at their desks and that was very good because there is still a lot of evidence that sitting too much is not good for us and that we need to move more” , says Bethany. Barone Gibbs, chair and professor in the Department of Epidemiology and Biostatistics at the WVU School of Public Health.

“However, blood pressure did not improve at all, not in resting blood pressure, ambulatory blood pressure, or pulse wave rate. That’s important because I think a lot of people use sit-stand desks and think it might help their blood pressure.”

According to the American Heart Association, almost half of American adults have high blood pressure. Increasing physical activity is a lifestyle change that can help lower the numbers.

“We know that moderate-to-vigorous intensity physical activity, such as brisk walking or cycling, absolutely lowers blood pressure,” Barone Gibbs said. “But over the last decade we now understand that even if you exercise as much as you should, which is 20 to 30 minutes every day, there are still 16 hours a day where you’re doing something. Otherwise, many people sit for most of the time.” of that other time.”

Barone Gibbs said previous observational studies – including some she led – suggested that people who sat a lot had worse cardiovascular health than people who were more active.

“Some of these showed that if you sat for long periods of time, bad cardiovascular things started happening, like blood pooling in your legs and your blood pressure would rise to compensate for the lack of circulation,” she said.

For the clinical trial, the researchers recommended that participants stand for 15 to 30 minutes every hour and take a walking break every hour. However, some stayed on longer than others, and that increased the level of aortic arterial stiffness, a factor that makes your heart work harder and marks the early stages of cardiovascular disease.

Although Barone Gibbs deemed the result “statistically significant, but not huge,” she said it suggests that prolonged static standing can have the same effect as prolonged sitting.

The reason, she explained, is a physiological mechanism called a muscular pump (or musculovenous pump), which helps circulate blood from the legs back to the heart.

“The veins in our legs have a one-way valve so that once the blood is pushed up, it can’t flow back down. That helps your heart pump the blood back up from your legs to your heart and brain,” she said.

“Every time you flex the muscles in your calves by walking or moving, those muscle contractions help push the blood up through this one-way valve. So if you stand at your desk and don’t move, it’s likely to result in the same blood pooling effects we see sitting, but even worse because it’s even harder for your blood to travel back to your brain when you stand.”

Their job was published in the news Circulation and will also appear in a special collection of null hypothesis articles.

“I know we’ve done a good study and even if it’s a null result, that’s important because we need to know what doesn’t work, just like we need to know what works to improve blood pressure,” Barone Gibbs said.

To conduct the study, Barone Gibbs and her team recruited 271 office workers who had elevated blood pressure and set the goal of increasing their physical activity during the workday.

Participants were given sit-stand desks and wearable activity trackers that buzzed if they didn’t get at least 250 steps per hour. They were also fitted with activity monitors and asked to keep a diary so researchers could understand their behavior on and off the job. Assessments include blood pressure and arterial stiffness.

Researchers found that standing outside of office hours had a positive effect on lowering blood pressure, a result that Barone Gibbs attributes to differences in the way people stand during leisure or work.

“You are more active when you are on your own time,” she said. “Say I’m watching my daughter’s soccer game, I might be standing, but I’m probably walking around, talking to people and watching the game. I’m not just standing still for a long time. I’m using my leg muscles and promoting of the blood flow.

“That’s an important distinction to make, while someone who uses a sit-stand desk, cashier, or other form of occupational standing is likely to stand still or static for extended periods of time. My hypothesis is that months of this static and standing for long periods of time can cause the arteries to stiffen over time.”

Still, Barone Gibbs says that sit-stand desks are helpful in several ways, including relieving chronic lower back pain and regulating glucose levels, as some studies suggest.

However, she advises people to avoid static standing and instead keep their muscles moving – a behavior she wants to address in her next study.

“What we want to explore are the little things you do at your desk, like lifting the heel to train the muscle pump, using a balance board or marching in place to get those muscles moving. Does that make it Is standing at a desk more helpful than harmful? We think this will be the case, but we don’t know for sure,” she said.

“We need more research on this so we can tell people what they can do to improve their health. Our job as researchers is to educate the public on how to most effectively spend their time and energy for health benefits.”