Throughout history there have been debates as to what content knowledge (CK) is of most value for physical education (PE). Much recent conversation has circulated around the hope that time spent in PE supports students' regular participation in physical activity (PA). Researchers' use of the term PA, however, often stresses the similarities while ignoring important differences. Utilizing teacher knowledge theory, feminist poststructural scholarship, and interpretive methodologies we attempted to better understand how teachers selected curricular content by examining their CK. We found that the teachers' PA biographies led them to develop deeply embodied and gendered knowledge and competencies, or "comfort," when it came to teaching particular PAs, and this was a major factor in how they selected curricular content. Implications of the study highlight the socially constructed nature of teacher CK and issues associated with secondary PE curricula and wider physical activity culture(s).