One of my more futile hobbies is trying to convince my friends to get more exercise: go for a walk at the beach or in the park, I plead. Their excuses are creative and inexhaustible. They have no comfortable shoes, their mother is ill, they are awaiting an important visit, they are recovering from a hard week at work. But as we continue to talk, I realize that they do get exercise: walking children to school or walking to a shop or bus stop, cycling to work or to visit friends. They are reminding me of what I already know but still forget: the only way to get the general population to get more exercise is to design our cities so as to incorporate physical activity into the daily routine. Since walking and cycling to needed destinations also increases social opportunities and contributes to a reduction in air pollution, traffic accidents, and expenses on fuel, it’s a big win on many counts. Lesson learned: stop nagging and keep fixing our cities!