Research published in the Archives of Internal Medicine shows prolonged sitting increases the risk of many diseases.
Sitting for more than 11 hours a day increases your risk of dying within three years by 40 percent. Sitting eight to 11 hours increases the risk by 15 percent.
Doctors say you don't have to exercise vigorously to cut those risks.
"We are built to move. We are built to perceive how we move. So the fact that people can spend as much time as they do sitting seems counter to the way we're designed," Professor of Kinesiology at Occident College Stuart Rugg said.
Experts say to stand up if you get a free moment and walk during lunch if you can.
Some companies have desks that allow you to stand. High-tech desks can even change from a sitting to a standing position.