This commercial "La craie" encourages everyone to practice 30 minutes of physical activity every single day without changing its habits. This 35-seconds film sounds like a pedagogic and practical invitation to change habits, for the best, without disrupting your day-to-day life. Because the city hides various possibilities of hiden physical activities, the film diverts urban elements (billboards, posters, furnitures ...) using varied typography, in order to reveal the differents possibilities of physical activities.