Project Summary The World Trade Center Health Program (WTCHP) tracks the ongoing health and well-being of first responders and people who lived and worked near the World Trade Center. As WTCHP participants age, it is important to identify pragmatic interventions to address their most common health conditions. Physical activity (PA) is a lifestyle intervention that can improve fatigue and overall health, and lead to other beneficial lifestyle changes for people with cancer. PA is safe in people with cancer, yet a majority do not meet exercise guidelines. Although PA has many health benefits, interventions to support patients are not routinely incorporated into clinical practice. Evidence-based guidelines recommend PA counseling in clinical care and health professionals strongly believe they should be doing this. However, a gap remains in implementing PA interventions at the point of care. WTCHP participants with cancer would benefit from an evidence-based motivational intervention to initiate or maintain PA. In the proposed study, we will use a Hybrid Type II randomized controlled trial to test the effectiveness and implementation of a brief motivational intervention to increase PA in a sample of WTCHP participants with cancer. To our knowledge, this is the first study to test and implement a motivational intervention to support PA within the WTCHP population. The study will employ a randomized wait-list controlled trial with a Hybrid (effectiveness–implementation) Type II design. Type II Hybrid designs test the effectiveness of a clinical intervention while simultaneously evaluating an implementation approach for embedding the clinical intervention at the point of care. Aim 1 will determine the effectiveness of a brief motivational intervention to increase PA in a group of WTCHP cancer survivors compared to an enhanced standard of care. Aim 2 will test the feasibility and potential utility of theory-driven implementation strategies to increase the adoption, fidelity, and sustainment of a brief motivational intervention to increase PA in a group of WTCHP cancer survivors compared to an enhanced standard of care. Participants will be randomized to the intervention plus a nutrition program or a nutrition program alone (enhanced usual care). The intervention includes brief motivational components (motivational interviewing, mobile health, and action planning) and participants will be encouraged to plan a PA program that fits their lifestyle and abilities. The intervention will last 3 months with a 3-month maintenance follow-up. Following the 3- month wait-list, participants in the control group will be offered the intervention. Developing evidence-based lifestyle interventions has the potential to lead to sustained behavior change that can alleviate health conditions and improve quality of life. The combination of testing effectiveness and implementation strategies in this study will speed the incorporation of evidence-based physical activity interve...