Assess graduate-level understanding of major behavior change theories and core constructs (e.g., Social Cognitive Theory, Transtheoretical Model, Health Belief Model, Theory of Planned Behavior, Self-Determination Theory) and the ability to select, apply, and justify these theories when designing, tailoring, and evaluating physical activity interventions for adults with chronic disease; includes mapping theories to behavior change techniques, addressing disease-specific barriers and facilitators, and evaluating theoretical fidelity and relevant outcomes.