In The Pasteurization of France, Bruno Latour argued that the rise of hygiene was dependent on collaboration between Pasteur, the hygiene movement, scientists and others. He also pointed at the importance of obligatory passage points such as the Pasteurian laboratory, to ensure the scientization and rationalization of hygiene. This article argues that there has been a similar process in elite sports, a ‘physiologization’ where scientists, sport organizations and specialized coaches have transformed training from a deeply personal and experiential matter to something universal and scientific. Physiologists made the test lab an obligatory passage point for athletes who wanted to compete on the highest level. Through theories of sportification and science and technology studies this paper analyses the scientization of endurance sports.