PROJECT SUMMARY/ABSTRACT Exercise is recommended as the first-line intervention for managing chronic pain in people with knee osteoarthritis (OA). However, activity and exercise related pain in people with knee OA leads to negative psychological beliefs including catastrophizing and fear avoidance that make exercise and activity challenging. Avoidance of activity and exercise perpetuates a vicious cycle of further pain. Racial and geographic disparities in access to exercise are also a reason for poor utilization. Mindfulness-based interventions can address the negative psychological beliefs in people with chronic pain and when combined with exercise, may address both physical and psychological impairments. Also, access to care is increasingly being addressed with the use of telehealth. This project will determine the feasibility of a novel telehealth mindful exercise intervention. Mindful exercise refers to application of mindfulness to structured exercise and daily physical activity. In this randomized controlled trial (RCT), participants with knee OA (n=62) will be assigned to a 10-week, group- based, telehealth - mindful exercise or only exercise arms. The RCT will be decentralized with recruitment, intervention, and outcome assessment all being conducted using digital tools including social media, electronic data capture system, and wearable sensors. The first aim is to determine the feasibility of a telehealth mindful exercise program compared to telehealth exercise in people with knee OA. The second aim is to examine the feasibility of a decentralized digital study in people with knee OA. The third aim is to examine the variability in key knee OA related outcomes in both groups to support the design of the future efficacy study. The long-term goal of this research is to determine the effectiveness of mindful exercise and translate it to clinical practice to reduce pain and improve function in people with knee OA. This study will provide information on the feasibility of the proposed intervention in people with knee OA and will also allow for optimization of digital strategies before conducting larger decentralized trials of intervention efficacy and effectiveness. The intervention is informed by a preliminary study aligned with Stage 1A of the NIH Stage Model for Development of Behavioral Interventions. The proposed study reflects Stage 1B before future efficacy and effectiveness studies can be undertaken. This research could yield a scalable and equitable intervention that is effective at addressing negative physical and psychological impact of knee OA, a disease that affects 1 in 10 people over the age of 50 in the US.