A new study finds that sedentary behavior is taking its toll on our mobility, especially for people 50 and up.

It’s no surprise that sitting for prolonged periods is not healthy for your body. It all takes a toll: sitting at a desk, sitting in traffic, sitting down to eat and, maybe worst of all, sitting on the couch and binge-watching TV.

A new study finds that all that sedentary behavior is taking its toll on our mobility, especially for people 50 and up. Older people who watched up to five hours of television a day and reported three or fewer hours of exercise a week were 65 percent more likely to have difficulty walking or be unable to walk almost 10 years later, according to a new study from the Milken Institute School of Public Health at George Washington University.

“TV viewing is a very potent risk factor for disability in older age,” said lead author of the study Dr. Loretta DiPietro, chairwoman of the Department of Exercise and Nutrition Sciences at the Milken Institute. “Sitting and watching TV for long periods (especially in the evening) has got to be one of the most dangerous things that older people can do because they are much more susceptible to the damages of physical inactivity.”

The study included more than 134,000 participants who were taking part in a national research project sponsored by the National Institutes of Health and AARP. It assessed all types of sedentary behavior, as well as light, moderate and vigorous physical activity in people ages 50 to 71 across eight to 10 years.

Those who sat the most and moved the least had three times the risk of difficulty walking by the end of the study compared to more-active participants.

For people who were the most physically active (seven or more hours a week), sitting for longer periods (up to six hours) was not associated with excess mobility disability.

It seems this may be a consequence of getting older. Younger people might be able to get away with sitting for long periods because they are physiologically more robust, DiPietro said. But after age 50, this study suggests, prolonged sitting becomes particularly hazardous. TV viewing in the evening may be especially detrimental to health because it is not broken up with short bouts of activity, compared with sitting during the day, DiPietro said.

To help reduce the risk, DiPietro suggests building more physical activity into daily life. For example, people who sit for long periods in front of a computer should get up every hour and/or switch to a standing desk. Commuters can park the car several blocks away from the office or decide to take the stairs.

Older people should walk about as much as possible throughout the day, and everyone should consider binging less on television — or at least marching in place during commercials or in between episodes.

“To stay active and healthy as you age, move more and sit less throughout the day every day,” DiPietro says.