A new study claims sitting for excessively long periods of time –even if you exercise regularly—is a risk factor for an early death. The researchers are recommending that you take a movement break every 30 minutes to reduce the risk.
The study focused on the relationship between the time spent sitting and the risk of early mortality of any cause. The findings were published online Monday in Annals of Internal Medicine.
On the bright side, the researchers found people who sit for less than 30 minutes at a time have the lowest risk of early death.
Sitting guidelines are needed for the public
The researchers noted people are less likely to have early deaths if they move around every 30 minutes than if they remain seated for extended periods of time.
“We think these findings suggest that it is simply not enough to be active or move at one specific time of the day, that is, exercise,” lead study author Keith Diaz, from the Center for Behavioral Cardiovascular Health at Columbia University Medical Center in New York, told Reuters. “We need to be mindful of moving frequently throughout the day in addition to exercising.”
Diaz cites a motto by the American Heart Association, which says “Sits less, move more,” and notes that such a simple guideline doesn’t quite cut it. Diaz told CNN that such guideline would be like telling someone to just “exercise without telling them how.”
He noted that exercise guidelines are usually precise. For instance, the U.S. Centers for Disease Control and Prevention recommends adults to do moderate-intensity aerobic exercises for two hours and 30 minutes every week, along with muscle strengthening activities two or more days a week.
“We need similar guidelines for sitting,” Diaz told CNN. “We think a more specific guideline could read something like, ‘For every 30 consecutive minutes of sitting, stand up and move/walk for five minutes at brisk pace to reduce the health risks from sitting.’”
Diaz added that the new study puts them a step closer to such guidelines, but more research is needed to verify their findings.
Sitting for stretches longer than 30 minutes can result in early death
To assess the potential health risks of sitting for extended periods of time, Diaz and her colleagues at Columbia, NewYork-Presbyterian/Weill Cornell Medical Center, and other centers turned to the Reasons for Geographic and Racial Differences in Stroke (REGARDS) project, which is sponsored by the National Institutes of Health.
The REGARDS project was originally envisioned to study why blacks –especially those in the Southern U.S.—have a greater risk of suffering a stroke than white individuals. Diaz and his colleagues tracked 7,985 black and white people, aged 45 or older, over an average of four years.
The participants were required to use hip-mounted accelerometers to measure their sedentary time. During the study period, the researchers recorded 340 total deaths considered “all-cause mortality,” or any death, regardless of their cause.
When they analyzed the data, Diaz and the co-researchers found that sedentary behavior accounted for 12.3 hours of an average 16-hour waking day. Diaz said that as we age, and our physical and mental functions decline, we become more sedentary.
Similar studies previously found that adults, on average, sit about 9 to ten hours per day. Diaz noted that the higher average on his study is likely because they focused on a middle- and older-aged population, and because the data was monitored and tracked, rather than self-reported.
The researchers found that as total sedentary time increased, so did the risk of early mortality, regardless of their sex, age, race, body mass index, or exercise habits.
“We found that there wasn’t a threshold or cutoff where one’s risk for death dramatically increased,” Diaz told CNN, noting that risk of death increased with more sitting. “To give you a specific number, those who sat for more than 13 hours per day had a 2-fold (or 200 percent) greater risk of death compared to those who sat for less than about 11 hours per day.”
Standing desks might not be the best alternative either
The study also found people who frequently sat in stretches less than 30 minutes had a 55 percent lower risk of death compared to those who usually sat for more than 30 minutes at a time.
Moreover, those who regularly sat for more than 90 minutes at a stretch had a nearly two-fold greater risk of early mortality, compared to people who almost always sat for less than 90 minutes at a stretch, according to Diaz.
When asked if, for example, a standing desk would be helpful for people who work desk jobs, Diaz said that there’s little evidence suggesting that standing is a healthier alternative to sitting. He noted that if your job or lifestyle requires you to sit for prolonged periods of time, the best suggestion he can make is to take a movement break every 30 minutes.
“Our findings suggest this one behavior change could reduce your risk of death,” said Diaz.