January 22, 2018
girl sitting with laptop
Be Well

Sitting Not So Pretty

by John Swartzberg, M.D.  

Sometimes it’s hard to follow advice to exercise more. It takes effort to go to the gym, and you have to find time for that three-mile walk. But just making an effort to sit less, by itself, can be beneficial. In fact, accumulating evidence suggests that reducing sitting time may be nearly as beneficial as increasing activity time.

Because of our desk-bound jobs, seated entertainments, and our reliance on cars and labor-saving devices, we’ve become increasingly sedentary in recent decades. Sedentary often means “not exercising,” but I’m going back to its basic meaning of “sitting” (from the Latin sedens). Studies have linked sitting a lot with cardiovascular disease, diabetes, obesity and other chronic disorders.

For instance, a Scottish study found that people who watched screen-based entertainment for more than four hours a day were more than twice as likely to have a heart attack or stroke as those watching for less than two hours. The effect was independent of factors such as weight, smoking and hypertension. The average American adult watches five hours of TV a day, and that doesn’t include home computer use. Spending long hours riding in a car every week also increases cardiovascular risk.

Another study, from the American Cancer Society, confirmed that it’s not just a matter of how physically active you are, but also how much time you spend sitting. It found that people who spend the most leisure time sitting have higher mortality rates, especially from cardiovascular disease—regardless of their overall physical activity level. That is, hitting the gym a few times a week won’t fully counteract the adverse effects of prolonged sitting. Still, the worst thing is to sit a lot and get little or no exercise, the researchers found.

The problem with sitting a lot isn’t just that it burns so few calories. Animal studies have found that because of lack of muscle activity, prolonged sitting can adversely affect blood cholesterol, triglycerides and blood sugar levels, as well as increase inflammation and fat storage.

So even if you exercise regularly, limit the amount of time you spend sitting, whether at a desk or in front of the TV. I’ve seen ads for “standing desks”—tall adjustable desks that allow you to stand while you work. And I’ve read about attempts to develop desks that are also treadmills or stationary bikes. That’s a bit extreme. Research suggests that all you need to do is break up prolonged sitting time by getting up and taking five-minute walks every couple of hours. Even just standing up for a minute or pacing around the room may help. And if you don’t exercise regularly, these short bouts may help break the inertia of sedentariness and lead you to longer, more strenuous activity.