sitting, watching TV, computer
A study reported in the Journal of the National Cancer Institute found a direct link between sedentary behaviour and colon, endometrial and lung cancerbasykes/Flickr

People who exhibit high levels of sedentary behaviour after age 60 are at a higher risk of being disabled, a new study has found.  The results remained unchanged irrespective of the amount of physical activity they managed to perform. 

Sedentary behaviour is a term used to refer to any activity performed in a sitting or lying position and that requires very less energy. Time spent in front of the TV, computer, activities like video game playing, workplace sitting, driving and reading are certain common types of sedentary behaviours. Disability refers to impairments, difficulties experienced while performing daily activities including bathing, using the toilet, eating, walking or getting up from the bed without any external help.

In the study, published in the Journal of Physical Activity & Health, each additional hour people spent for sitting nearly doubled their risk of disability. So a 65-year-old woman who remains sedentary for 13 hours has double risk of being disabled, compared to another woman of the same age who is sedentary for 12 hours, the researchers said.

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

For reaching a conclusion, Dunlop and colleagues looked at 2,286 American adults, aged 60 and above, as part of the National Health and Nutrition Examination Survey. Participants shared similar health features and engaged in the same amount of moderate activity (defined here as walking briskly).

For more than two years (2002-2005), the participants wore accelerometers (devices that use electronic motion sensors to measure quantity and intensity of physical activity). Results showed that sedentary behaviour posed the same health risk as lack of any physical activity. Concerned with the findings, Dunlop recommended aged people to restrict the time they spend for sitting or related activities.  "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.

However, researchers said that their study couldn't establish a cause and effect between the two- sedentary behaviour and disability.