Ostlind E, Anna AS, Eek F, et al. - This study sought to present physical activity (PA) patterns and adherence to wearable activity trackers (WAT)-use during an intervention among participants of working age with hip and/or knee osteoarthritis (OA). Researchers further investigated the relationship between self-reported joint function and PA. They enrolled individuals of working age with hip and/or knee OA who used a WAT, Fitbit Flex 2, for 12 weeks. Individuals evaluated their PA in the Fitbit app. It has been recorded that the majority of participants reached 7,000 steps/day and the recommended 150 min in MVPA per week. Nevertheless, PA reduced slightly but gradually over time. The data illustrate that adherence to using the Fitbit was high but also reduced during the intervention. Among participants of working age with hip and/or knee OA, understanding PA patterns and the use of a Fitbit to promote PA could be beneficial in tailoring interventions.