The course main objective is to inform and discuss in great details the latest advancements in low power sensing technology, energy harvesting and their heterogeneous integration for wearable smart system applications. Technological roadmaps of performance and future evolutions will be presented. The low power wireless communications are discussed from the point of view of existing standards and challenges for reducing the energy per communicated bit. Another objective is to detail some key future applications for wearable sensing and computing with main emphasis on: (1) medical Diagnostics, monitoring and prevention and (2) sports, fitness and activity monitoring applications. We analyze the benefits of autonomous smart system technology from many different points of view, including that of the individual, the physician, health care management, and society in general. We provide a rationale on the role of such technology as a component of the care cycle and the changes it can induce by reinforcing preventive strategies.