If people sat for less than three hours a day, the average life expectancy for Americans would be 80.5 years instead of the current 78.5 years, according to the study published Monday by the online journal BMJ Open.

Researchers analyzed data collected for the National Health & Nutrition Examination Survey and found that almost half of people reported sitting more than six hours a day and 65 percent said they spend more than two hours a day watching TV.

"Sitting is a dangerous risk factor for early death, on par with smoking and being obese," Peter Katzmarzyk, a researcher at the Pennington Biomedical Research Center in Baton Rouge and lead author of the study, said in a USA Today article about the findings.

To combat sitting down for long periods of time, experts suggest getting up to talk to co-workers, standing up, doing another nonsedentary activity while watching TV or making time to stretch while sitting down.

More Information: Read The Study