Some engineer has written a book called The Hacker's Diet, complete with an exercise program and computer tools. I am reminded that I really should exercise more.
My personal technique involves wearing a step counter to keep track of how little I move around during the day. I used to do some yoga exercises, but I misplaced the book last time I moved. I suppose that is yet another reason for me to go through the stack of boxes in my office. Hey, if I start doing stretches on the floor, I bet I'd want to vacuum the carpet more often. Amazing how good patterns can reinforce each other.