The human foot is a flexible structure characterized by a pronounced medial longitudinal arch (MLA) that compresses and recoils during running. That process is actively driven by the intrinsic foot muscles and requires a proper stability of the MLA. This introduces the concept of foot core stability. Because the intrinsic foot muscles are often neglected by clinicians and researchers, the purpose of this article is to provide some guidelines for incorporating foot core training in prevention or rehabilitation programmes for runners.