While there is sufficient evidence to suggest that physical activity is inversely related to lifestyle diseases, researchers are far from being certain that this evidence extends to children. Nevertheless, the school physical education curriculum has been targeted as an institutional agency that could have a significant impact on health during childhood and later during adulthood if individuals could be habituated to assume a physically active lifestyle. The purpose of this article is to examine the recontextualization of biomedical knowledge into an ideology of healthism in which health is conceived as a controllable certainty and used as a pedagogical construction to transform school physical education. Using a Foucauldian perspective, we explore how the atomized biomedical model of chemical and physical relationships is constructed, reproduced, and perpetuated to service and empower the discourse and the practices of researchers and scholars. In this process the sociological or cultural aspects of public health are marginalized or ignored. As a result of this examination, alternative approaches are proposed that engage the limitations of the biomedical model and openly consider the insights that are available from the social sciences regarding what participation in physical activity "means" to individuals.