Physical education has been compulsory in France since 1880. Between 1936 and 1950, expansion intensified and extensive changes were made to course content. This article assesses the ramifications of these choices through an in-depth study of four variables that defined its instruction. Even if priority was given to generalisation and equal access to knowledge, research revealed an upsurge in the fight against real or presumed student vulnerability. At the time, a strong consensus emerged with the commitment to fight frailty. This was all the more the case for young girls as they belonged to a specific group with respect to their physical make-up. The school system stressed the relevance of instruction adapted to girls even if emphasis was placed on the cultural aspect of sport content. The pedagogical programmes put into effect for youths based on these guidelines confirmed this trend. This situation raised concerns as to the role of the school system in the development of social stereotypes through a discipline that would become the focus of the French education system.