Physical activity plays a fundamental role in contrasting physiological deconditioning during ageing. Considering the complexity of the modifications that can occur in the physical activity domain, international guidelines recommend that older adults engage in a combination of aerobic, strength, flexibility, and balance training to promote active ageing and maintain adequate health status. For this reason, virtual coaches must be designed to prescribe appropriate physical activity plans in each of the specific target sub-domain. Technological solutions based on wearable devices and digital games are promising can be the key to a successful system. This chapter describes the physiological bases and the technological approaches implemented by the NESTORE system to evaluate users’ functional abilities and to propose a comprehensive and individualised coaching plan in the physical activity domain according to the internationally recognised guidelines. The main technological NESTORE components, co-designed together with users to monitor their status and behaviour and coach them to perform effective physical activity, are (i) the NESTORE wristband that will assess the users’ performances and monitor the main physiological parameters during aerobic activity and (ii) the NESTORE Pocket Odyssey mobile game that will engage the users during physical activities in the strength, flexibility and balance domains.