Facing physical inactivity, stress, chronic illnesses and even heavy illnesses, sport is an issue for well-being. France has made the courageous choice of sport by prescription. State with welfare inheritance or solution for the future? What is the cost and benefit of the Society? What levers for patients and individuals? What are the brakes for medical staff? How can we help to cure the evils of the 21st century through sport? What examples in Europe?