Fibromyalgia (FM) is a chronic pain condition that disproportionately impacts Veterans. Individuals diagnosed with FM patients experience lower self-esteem and positive affect, as well as greater levels of depression, anxiety, negative affect, and pain catastrophizing. Among those experiencing FM, clinical and experimental pain are associated with specific dispositional trait profiles, which are indexed by levels of negative affect and positive affect. Neuroinflammation and inflammation also play a role in FM- related affect and pain. Recent studies that have highlighted neuroinflammation and inflammation as physiological mechanisms associated with changes in dysregulated affect and chronic pain. Veterans with FM can ameliorate their dispositional traits-i.e., increasing positive affect and reducing negative affect-by participating in exercise. However, a gap exists regarding how to optimally engage Veterans with FM in an exercise program. Thus, to fully take advantage of all potential therapeutic benefits of exercise for FM, there is a critical need to identify those factors underlying exercise engagement for FM pain management. The purpose for this study is to 1) determine associations of dispositional trait styles, neuroinflammation, and inflammation with pain outcomes in Veterans with FM; and 2) develop and design a Veteran-informed exercise program.