Science has made it clear: sitting is killing you. Even if you exercise regularly, it does not come close to balancing the damage you are doing by sitting all day at a computer or watching TV.
On top of that, most of us sit wrong. Are you making these posture errors while sitting?
Sitting on a Dog
Sitting Beneath Levitating Desk
Sitting in a Closet
Sitting on Top of a Commuter Train
Sitting On A Scotch Pine
Take inventory of your sitting habits, and make changes where needed. It will prolong your life.