With a point of departure in a transactional understanding of epistemology, the purpose of this paper is to explore practical epistemologies in physical education (PE) by investigating how knowledge is produced and reproduced in students' and teachers' actions in PE practices posted as clips on the user-generated video-sharing website YouTube. YouTube can be understood as a disordered public video archive of (in this case) ongoing PE practices created by both students and teachers. With a transactional understanding, knowing, and in consequence questions of epistemology, can be conceived of as something we do, something practical. In this paper, practical epistemologies in PE are investigated by exploring ends-in-view and habits-of-action in students' and teachers' actions in PE practice. The practical epistemologies identified in the study are as follows: (i) knowing by doing correct movements; (ii) knowing by trying; (iii) knowing by imitating; (iv) knowing by praising and cheering; (v) knowing by cooperating; (vi) knowing by creating; (vii) knowing by being changed into gym clothes; (viii) knowing by acting in a certain locality; and (ix) knowing by resisting. The categories represent "different" ways of how knowledge is produced and reproduced in PE practice, and describe the functions that different actions and actors have in how knowledge is produced and reproduced as well as in the direction this takes. (Contains 6 notes.)