The Portuguese census of 2011 showed that 22,5% of the population of Região Centro was 65 years old or more. The increase in the elderly population leads to the need to promote healthy aging, with autonomy and independence, and preserving the functional capacity. As people get older, injuries and health conditions that impact on their wellbeing must be taken into account, and understanding what is adequate requires specialized knowledge and training. If people are left alone deciding their own activity level, they can be too aggressive and aggravate their injuries, create new ones and refrain themselves in exercising more, or too conservative and in the long run they will have an activity level under their potential and below what is recommended. In this paper we present SmartWalk, a project that aims to create a monitoring system of wellbeing and physical activity in the context of Smart Cities. The project is more than a smartphone application, as it will have health professionals operating the system and will take into consideration contextual and user specific information. The service is about helping people to have the best possible activity level, and do so without disrupting their routines.