Over the three-year project period, PreventIT developed and tested two lifestyle-integrated exercise intervention programmes to prevent future functional decline in adults aged 61-70 years: the paper-based, instructor-led aLiFE and the app-based eLiFE. A motivational strategy was developed to support behavioural change towards a more active, healthy lifestyle. In addition, several tools were developed to screen the risk for future functional decline, personalise the intervention to individual users, assess behavioural complexity, and allow users to test their own function unsupervised. Results from the feasibility study indicated that the developed interventions were feasible and safe, with good intervention uptake and acceptable adherence. Participants were aware that the technology was not fully developed, but they liked the concept of lifestyle-integrated activities, managed to change their daily routines towards increased activity, and were positive about the proof-of-concept technologies integrated in the app-based eLiFE.