The typical American adult spends 3 to 5 hours a day watching TV. Each hour of TV averages about 12 minutes of commercials. Researchers had men step in place at a moderate pace during the commercials. The men burned 150 calories, more than double the amount of calories they would have used sitting and watching TV. Multiply this times 3 to 5 hours of TV watching each day and you could burn 200 to 350 extra calories a day. Get out of your recliner!