If you’re 60 or older, every additional hour a day you spend sitting is linked to a 50 percent greater risk of being disabled — regardless of how much moderate exercise you get, reports a new Northwestern Medicine® study.


The study is the first to show sedentary behavior is its own risk factor for disability, separate from lack of moderate vigorous physical activity. In fact, sedentary behavior is almost as strong a risk factor for disability as lack of moderate exercise.


If there are two 65-year-old women, one sedentary for 12 hours a day and another sedentary for 13 hours a day, the second woman is 50 percent more likely to be disabled, the study found.


“This is the first time we’ve shown sedentary behavior was related to increased disability regardless of the amount of moderate exercise,” said Dorothy Dunlop, professor of medicine at Northwestern University Feinberg School of Medicine and lead author of the study. “Being sedentary is not just a synonym for inadequate physical activity.”


Disability affects more than 56 million Americans. It’s defined by limitations in being able to do basic activities such as eating, dressing, or bathing oneself, getting in and out of bed, and walking across a room. Disability increases the risk of hospitalization and institutionalization and is a leading source of health care costs, accounting for $1 of every $4 spent.


The study was published February 19 in the Journal of Physical Activity & Health.


The finding — that being sedentary was almost as strong a risk factor for disability as lack of moderate vigorous activity — surprised Dunlop.


“It means older adults need to reduce the amount of time they spend sitting, whether in front of the TV or at the computer, regardless of their participation in moderate or vigorous activity,” she said.


Visit the Northwestern News Center for the full story. Visit the Journal of Physical Activity & Health to read the study.