While watching television and running may motivate people to workout, it's worth noting, that when using a treadmill, you should keep your head, heart, and hips aligned frontwards while running and not change your posture due to being glued to the screen. You are more likely to lose concentration watching television while running on a treadmill. which can get dangerous as well. Being too engrossed with the action on the screen may also make you repeatedly perform the same exercise routine unaware without changing to different workouts resulting in missing the goals you set for that workout.