After analyzing the data, researchers found an association between prolonged sitting and risk of early death from all causes. Specifically, they found that those participants who said at the start of the study that they sat for more than 11 hours daily were 40 percent more likely to have died during the next three years than those who said they sat for four hours or less daily.
People who reported sitting for eight to 11 hours daily had a 15 percent higher risk of dying than those who sat less than four hours a day.
And, yes, the results took into account the participants’ physical activity.
“Prolonged sitting is a risk factor for all-cause mortality, independent of physical activity,” the researchers concluded. They also found that the findings were consistent across all age groups and in both men and women — and even after adjusting for such factors as weight and pre-existing health conditions, including heart disease and diabetes.
“To put this in perspective,” wrote two Australian epidemiologists in a commentary that accompanied the study, “30 minutes of physical activity is as protective an exposure as 10 hours of sitting is a harmful one.”
This study is just the latest in a slew of similar research that has pointed out an adverse association between early death and different types of prolonged sedentary behavior, including TV viewing, video-game playing, driving in a car, and working at a job that requires sitting.
Some of the research isn’t all that new. As the commentary authors point out, a 1966 study “reported that workers in occupations requiring much sitting (London bus drivers and mail sorters) had higher incidences of cardiovascular disease than did workers who were required to stand and ambulate (bus conductors and postal workers).”
Still, the current study is not designed to prove cause and effect. As an observational study, it comes with all sorts of caveats. To begin with, the participants’ initial health and lifestyle data were collected through questionnaires, an unreliable source of information no matter how standardized they are. In addition, certain as-yet unidentified factors may be behind the study’s results. For example, the people who reported sitting for long periods of time may have had undiagnosed illnesses at the study’s start.
The authors of this study acknowledge these limitations, of course. In fact, they note that sedentary behavior research “is still in its infancy and that more high-quality prospective studies are needed.”
But they’re also calling for public health program to “focus not just on increasing population physical activity levels but also on reducing sitting time, especially in individuals who do not meet the physical activity recommendation.”
In other words, we may need to add “reduce daily sitting time” to our to-do list for a healthier lifestyle.
It wouldn’t hurt any of us, of course, to stand up and move around more often. As the study’s background information points out, the average adult spends more than 90 percent of his or her leisure time sitting (or lying) down.
So don’t just sit there. Get up from your computer and, well…move.