This essay explores the broad and fast-developing field of the socalled Healthy, Active City and shifts the theoretical point of view from a medical, almost curative, issue to an urban one. Urbanism is therefore affirmed as a fundamental and preventive discipline, capable of enhancing the health and quality of life of urban populations. Especially in times of a global pandemic such as the one that began in early 2020, the relationships between urbanism, urban health, and the built environment are of fundamental importance. The author tackles, from an urban design and planning perspective, the complex connections and cause-effect processes that link the characteristics of our cities to the well-being of populations, focusing on the dichotomy between urban and human bodies, with specific emphasis on physical activity because of its role as a principal contributor to health conditions. For a long time, such relationships were predominantly approached from an epidemiological and so- cial point of view, which saw the features and structure of the city as the determinants of the levels of health and physical activity; yet these were rarely investigated in depth.