If this newly discovered data isn't enough to get you off the couch and out for a walk, I don't know what is. Allow me to lay it on you: Going from no exercise at all, to one 20-minute brisk walk per day, offers a 20-30 % reduction in overall mortality risk. Excuse me while I go dig out my walking shoes. Talk amongst yourselves in the comments. While typing on your mobile device. And walking around the block.