There are opportunities to exercise at no cost in time. I usually bike to work and to go into town, which takes no longer than driving, and the harder I ride, the less time it takes. I walk up four stories to my office, which takes no longer than the lifts, and I'm usually up and down those stairs 2 or 3 times in a day. I play taiko, which is great fun, but is also pretty strenuous. So that's 7 miles of biking and around 100 vertical feet of stair-climbing every working day, and a cardiac workout of a few hours a week, for free.

There are other things I do, but these are the ones that effectively take neither time nor money to do.