Sitting is unhealthy. Millions of Americans are sitting more than ever.

The average adult in the US spends approximately six and a half hours per day, an increase of approximately one hour per day since 2007. For teenagers aged 12 to 19, this number is eight hours per day. More time spent on computers is largely responsible for this tendency to sedentary behavior, according to an analysis, published in the Journal of the American Medical Association, 16 years of data collected by the National Center for Health Statistics. Although 60% of the American population spends at least two hours a day watching television, this percentage has remained stable in recent years. But the number of computer users outside of school or work has increased for all age groups. Today, 50% of adults spend at least one hour of their personal time each day at the computer, compared to 29% in 2003, and about 53% of teens and 56% of children now spend as much time on their computer. In addition, among those who use computers, as many as one in four do so for at least three hours each day – outside of work or school hours. The time spent by sitting people worries health experts. Research has linked sedentary behavior to increased risk of obesity, diabetes, hypertension, heart disease and more. When people are sitting and not physically active, their muscles and bones can weaken and they are more likely to gain weight because they burn fewer calories. Some experts believe that inactivity also affects blood circulation and the immune system. Sedentary people also do not benefit from the energy, mood and quality of sleep that come from regular activities.

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