<p>This article critically examines research on gender/sex in sports science, which has traditionally been divided between social science and natural science approaches dealing with gender or sex. It introduces the concept of an epistemological as well as ontological entanglement of sex and gender, an idea that is gaining increasing recognition in health sciences. I argue that in sport-related research, sex and gender should also be conceptualized and studied as intertwined, and discuss three areas of gender/sex research in sports science from this perspective.</p>