If you’re sitting all day, science shows how to undo the health risks. Take ‘activity snacks’ every 30 minutes.


ISLAMABAD: A short stroll every half hour may help undo the health harms associated with prolonged periods of sitting, a new study finds.
Mounting evidence has suggested that sitting for long periods of time — an inescapable fact of life for many workers — is hazardous to health even for those who exercise regularly.
In the new study, volunteers who got up and walked for five minutes every half hour had lower blood sugar and blood pressure than those who sat continuously. The researchers also found that walking for one minute every hour helped with blood pressure, but not blood sugar, according to the small study published in Medicine & Science in Sports & Exercise.
“If you have a job that requires you to sit most of the day or have a largely sedentary lifestyle, this is one strategy that could improve your health and offset the health harms from sitting,” said the study’s lead author, Keith Diaz, an associate professor of behavioral medicine at the Columbia University Vagelos College of Physicians and Surgeons.
It’s not clear why sitting for long periods uninterrupted is bad for your health, but Diaz suspects at least part of the explanation is that while we’re sitting, we aren’t using our leg muscles.
“Muscles serve as important regulators of blood sugar levels,” he said. “If we don’t use them, things don’t work right.”
When it comes to blood pressure, moving around helps improve circulation, Diaz said. “When you’re sitting, the blood pools in the legs,” he added. “When you regularly activate the muscles in the legs, it helps restore regular blood flow.”
‘Activity snacks’ every 30 minutes
To look at the best way to battle the deleterious effects of sitting, Diaz and his team tested four different ‘activity snacks’ in 11 volunteers: one minute of walking after every 30 minutes of sitting, one minute after 60 minutes of sitting, five minutes after 30 minutes of sitting and five minutes after 60 minutes of sitting . The effects of each of those strategies were compared to those from sitting with no breaks.

Each of the 11 adult volunteers came to the researchers’ lab where they were seated in an ergonomic chair for eight hours, getting up only for a bathroom break and whatever activity snack they’d been told to perform. All 11 ran through each of the strategies, one at a time, as well as an eight-hour period in which they only got up for bathroom breaks.
Blood pressure and blood sugar were measured during each phase of the study. The strategy that worked best was five minutes of walking for every 30 minutes of sitting. This strategy also had a dramatic effect on how the volunteers’ bodies responded to large meals, producing a 58% reduction in blood pressure spikes compared with sitting all day.