Study Finds Sitting All Day Without Breaks Increases Mortality Risk—Even if You Exercise

Time for a stretch break! A new study published in the Journal of the American Heart Association found even further evidence that sitting for hours on end without any breaks to stand up and move is associated with greater risk of heart disease and all-cause mortality—even for those who engage in formal, moderate or vigorous exercise.

Being sedentary, or spending prolonged periods of time sitting/lying down without interruption, and lacking frequent or adequate physical activity, has been linked to serious health outcomes, including age-related cognitive degeneration, increased cardiovascular disease risk, metabolic conditions, and more.

This study seems to suggest that the negative impacts of uninterrupted sedentary behavior outweighs the effort and potential benefits of exercise; the total amount of time spent sedentary each day, and the length of each sedentary period, are what pose a threat to overall health, despite how healthy your lifestyle and behaviors are outside of that sedentary time.

Study Findings

The study’s authors analyzed the data and behaviors of 6,489 women in their 60s to 90s from the Women's Health Initiative Objective Physical Activity and Cardiovascular Health (OPACH) Study, using a novel algorithm to examine both total sedentary time and the duration of each period spend sitting.

Results found that women who were stationary for 11.7 hours or more per day faced a 30% higher mortality risk. “Sedentary behavior is defined as any waking behavior involving sitting or reclining with low energy expenditure,” said study co-author Steve Nguyen, PhD, MPH, a postdoctoral fellow at the University of California San Diego Herbert Wertheim School of Public Health and Human Longevity Science, in a university press release.

The paper concludes that “[h]igher total sitting time and longer mean sitting bout duration are associated with higher all‐cause and CVD mortality risk among older women. These data support interventions aimed at reducing both total sitting time and interrupting prolonged sitting.”

How Sitting for Hours Affects Your Body and Overall Health

“When you're sitting, the blood flow throughout your body slows down, decreasing glucose uptake,” lead author Andrea LaCroix, PhD, MPH, distinguished professor at the Herbert Wertheim School of Public Health, explained in the press release. “Your muscles aren't contracting as much, so anything that requires oxygen consumption to move the muscles diminishes, and your pulse rate is low.”

Previous research seems to have indicated that getting a certain amount of exercise can make up for, or offset, the negative effects of long-term sedentary behavior every day. But according to LaCroix and Nguyen’s paper, even women who exercised moderately or vigorously were still vulnerable to the same increased risks if they were sedentary for too long throughout the day.

How Often Should You Take Breaks?

“The risk starts climbing when you’re sitting about 11 hours [total] per day, combined with the longer you sit in a single session,” LaCroix said. “For example, sitting more than 30 minutes at a time is associated with higher risk than sitting only 10 minutes at a time.”

She also notes that it’s unrealistic, or downright impossible, for most people to stand up and stretch every 10 minutes—what if you’re a long-haul truck driver or need to engage in deep, focused work? That said, any breaks that you can take, do take them. If it’s once every 30 minutes or 20 minutes, that’s way better than nothing. If you want to sneak in a quick stretch, march in place, hold a plank, or walk around the office floor, that’s great (even getting three minutes of exercise at a time can have awesome health benefits!)—but all you really need to do is stand up and shift your weight around. “[You] don't have to go anywhere, [you] can just stand for a little while,” LaCroix says.