About two months ago I got in the habit of climbing 8-9 flights of stairs 3-5 times a day in my office building. Instead of using the restroom on my eighth floor, I go to the one in the basement via the elevator and return by the stairs. I started because I notice that I was not getting to the gym enough to maintain my aerobic stamina—and I was putting on weight. It also helps me burn off accumulated nervous energy from sitting at my keyboard or the opposition, feeling sluggish because of lack of movement.
An additional payoff in my yoga practice is that I can hold chair pose (Utkatasana) without my thighs screaming for mercy after 20 seconds.