The risks of an overly sedentary lifestyle

Moving every 30 minutes is one way to reduce the harmful effects of a sedentary lifestyle.

Health experts call it "sitting disease." It refers to when people spend more of their time behind a desk or steering wheel of a car or planted in front of a television than they do engaging in physical activity. According to the American Heart Association, sedentary jobs have increased by 83 percent since 1950, and technology has reduced many people's need to get up and move. Inactivity is taking a considerable toll on public health.

A study from the University of Cambridge equated inactivity with being...