Luc Collard is a sociologist and University Professor of STAPS (Sciences et Techniques des Activités Physiques et Sportives) at Paris Cité University. Initially a Physical Education and Sports teacher (CAPEPS in 1988, agrégation in 1991), he soon became interested in the motor action perspective - Praxeologie motrice - developed by Pierre Parlebas. It was from this perspective that he defended his thesis on risk and risk-taking in sports games (1997) - demonstrating the educational value of high-risk sports with the help of "experimental game theory". He also uses game theory to study swimming tactics, arguing for the emergence of a fifth stroke. Luc Collard initiated the first 5e nage competitions in Paris. His book "La 5e Nage" has been translated into 8 languages. Luc Collard is behind the first 5th swimming competitions organized since 2019 under the aegis of the FFSU (Fédération Française du Sport Universitaire) in Ile de France.