Too much time sitting and watching TV is taking years off your life expectancy, a study says. Researchers arrived at the conclusion from the results of five studies that explored the effects on nearly 167,000 people of sitting and watching television.

Peter Katzmarzyk, the study’s lead author and a professor at the Pennington Biomedical Research Center in Baton Rouge, La., said “…the study doesn’t establish a direct cause-and-effect relationship between sitting, TV watching and death. But the evidence suggesting an association between shortened lives and sedentary activities, like TV watching and driving, is piling up”

There also seems to be something about sitting itself that is bad for one’s health. Studies in both animals and humans have found that sitting leads to changes in resting glucose levels and blood pressure, and that lots of sitting bumps up levels of certain biomarkers of cardiovascular disease and cancer.

“The take-home message is clear: we may not know exactly why sitting is bad for you, but if you reduce the amount of time spent sitting, there are real health benefits,” the researchers said.

Katzmarzyk said since many people spend at least eight hours each day sitting at a computer, the workplace is an ideal place to start looking for ways to reform behavior. People can get up to talk to colleagues instead of emailing them, or spend a few minutes of their lunch breaks taking a short walk. And of course, a good place to start making changes is by squeezing the recommended 30 minutes of exercise into every day.