Get up, stand up, it just might help your heart

By Lisa Rapaport

(Reuters Health) - People who sit less - even if all they do is stand up without walking around - may improve their heart health by lowering levels of sugar, fats and cholesterol in their blood, an Australian study suggests.

Researchers asked 782 men and women to wear activity trackers around the clock for one week, measuring how much time they spent sleeping, sitting or lying down, standing and walking or running. Then, the researchers did blood tests to see how these activities influenced specific indicators of heart health.

"Just being upright increases muscle contractions in the large postural muscles of your legs and back - and that is beneficially associated with your blood sugars and fats," lead study author Dr. Genevieve Healy, of the University of Queensland, said by email. "This is some of the first evidence of the potential benefits of standing."

Plenty of research has shown the benefits of physical activity, and the potential health hazards of an extremely sedentary lifestyle. Healy and colleagues designed the current study to see if even standing might be better than sitting for prolonged periods of time.

Study participants were typically around 57 years old, with ages ranging from 36 to 80, and 57% were women.

Most participants provided researchers with at least four days of data from the activity trackers, and 572 of them stuck with the experiment for all seven days.

On average, people wore the trackers for almost 16 hours a day and spent about nine hours sitting, five hours standing, two hours walking and one hour engaged in moderate to vigorous physical activity.

Each extra two hours a day spent sitting was associated with added pounds and thicker waistlines, as well as higher levels of sugars and fats in the blood and lower levels of HDL cholesterol, the researchers estimated.

Excessive sitting was linked to more sugars and fats in the blood even when people also got more moderate to vigorous physical activity.

Conversely, each additional two hours of standing was tied to lower levels of sugars and fats as well as healthier cholesterol test results, and adding exercise to the mix helped lower blood sugar even more.

When people walked an extra two hours a day, they weighed less and had smaller waists in addition to having better results on blood tests for sugars, fats and cholesterol.

The study doesn't prove that standing or walking causes better health outcomes. And more research is needed to confirm the findings in larger studies, with people randomly assigned to different activity levels. But the results still point to the potential benefits of reducing sedentary time, the researchers note in the European Heart Journal, July 30.

Because many people spend most of their sitting hours at work, offices might offer treadmill desks or workstations that can easily be converted to standing desks for at least part of the day, the researchers write.

The findings also show that public health approaches to curbing sedentary behavior can't be focused exclusively on promoting regular exercise, Dr. Francisco Lopez-Jiminez, a researcher at the Mayo Clinic in Rochester, Minnesota, writes in an accompanying editorial.

When sitting for hours is unavoidable, people can try to make that time more active by using a miniature elliptical stepping machine under their desk or by modifying a regular desk to allow some work to be done standing up, he told Reuters Health.

"Somebody who is very, very active all day might not need to be doing special exercise five days a week," he said. "But for someone who sits all the time, a 30-minute run at the end of the day may not be enough to counter what happens from sitting too much"

SOURCE: http://bit.ly/1fO60rt and http://bit.ly/1KU0yRw

Eur Heart J 2015.

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