According to science, after the age of 25, every hour of television that you watch shortens your life by 22 minutes. That means we're already undead because we watch a lot of television. Well, not really. The reasoning behind it comes more from the inactivity involved in being comforted by the warm glow of your childhood babysitter, not the brain-decaying programming spewing forth from your flat-panel hellgate. So people watching an all-day marathon of America's Next Top Model while chugging away on their NordicTracks needn't worry.
Oh, and don't think that just because you watch all of your shows on The Hulu or The Youtube — or some illegal video site run out Kim Jong-il's basement — that you're safe from TV's death grip. The same study says that six hours spent in front of a computer each day increases your risk of death by 40%. Granted, that sounds pretty vague, but it's enough to get us up off our butts every once in a while.