The word "parkour" derives from "parcours du combattant" (obstacle course), the classic obstacle course method of military training proposed by Georges Hébert. Raymond Belle used the term ""les parcours"" to encompass all of his training including climbing, jumping, running, balancing, and the other methods he undertook in his personal athletic advancement. His son, David, further developed his father's methods and achieved success as a stuntman, and one day on a film set showed his 'Speed Air Man' video to Hubert Koundé. Koundé suggested he change the "c" of ""parcours"" to a "k" because it was stronger and more dynamic, and to remove the silent "s" for the same reason, forming ""parkour"".