Aim The aim of the study is to answer the following research questions: "What affects teachers' interpretation of knowledge requirements?" and "What affects teachers' assessment of knowledge requirements?". Method The data has been gathered through qualitative semi-structured interviews with upper secondary school teachers in sports and health in the Stockholm area. The material was analyzed after the transcription by a discourse analysis based on two themes from the study's questions, where the teachers' statements were divided into categories with influence factors. Based on the categories, three discourses were found, activation discourse, sport discourse and education discourse were visualized, which were later used to discuss the results of the material. Results The three factors that affect secondary school teachers' interpretation of the knowledge requirement are: the teacher's background, the teacher's interpretation of the concepts of movement capability and physical literacy, and whether the teachers have collegial cooperation. The four factors that affect the assessment of the knowledge requirement are: collegial cooperation, access to premises, how the teachers interpret the grades in the knowledge requirement and their attitude toward the knowledge requirement. Conclusions The teachers interpret the knowledge requirements differently, which seems to be due to their different views on what should be learned in the subject, which can be related to their sports background. This also influences their different views on how the concept of movement capability shall be realized and assessed in the subject. The teachers emphasize the importance of having collegial cooperation, both to interpret and assess the knowledge requirement, indicating that the knowledge requirement is not sufficiently clearly designed to enable teachers to interpret it on their own.