Monitoring physical activity, function and capacity through Digital Health Technology (DHT) has a high potential to benefit healthcare providers and patients. Current practices of observing physical function and capacity use standard tests such as the 6-Minute Walk Test (6MWT) or the Timed Up and Go, which collect momentary information on the patient’s health status. The use of DHT is demonstrated to enhance these types of assessments, from the instrumentation of physical tests with technology to the analysis of digital biomarkers collected during one’s daily life. Research at national and international levels investigates these topics on a large scale; however, it often lacks transparency and details in regards to used algorithms and data quality. These aspects are crucial when implementing technology for health-related purposes, where data quality and methods accuracy are fundamental for impacting clinical practices. This thesis investigates how DHT can support physical testing in ecological or community environments, answering three main research questions related to data collection and quality, algorithms, and the association between daily life physical activity and physical tests. Throughout six articles, this work investigates methods for inferring walked distance during the 6MWT in indoor and outdoor conditions, highlighting the importance of data quality collected through DHT. It shares a publicly available dataset providing inertial and localization information of patients and healthy volunteers. Lastly, it reports on insights and common procedures regarding DHT used during everyday life and its relation with physical tests. Foundations are laid for future work in this domain.