BackgroundMusculoskeletal conditions are leading contributors to global disability and place a significant economic burden on health systems. Optimal physical activity is a key recommended strategy for managing musculoskeletal conditions, yet many individuals struggle to sustain activity levels following the completion of exercise rehabilitation programmes. Identifying and understanding the factors that influence sustained physical activity may aid intervention design and benefit future patients. The aim of the study was therefore to explore the evolving needs of participants completing a joint pain exercise rehabilitation programme and identify factors which influenced sustained physical activity beyond programme completion.MethodThe current study adopted a longitudinal semi-structured interview methodology, building upon our initial study conducted at the end of the supported phase (week 12). Semi-structured interviews were conducted at week 24 (mid-term follow up), and at week 36 (long-term follow-up), during which participants were expected to self-initiate engagement with structured physical activity. Reflexive thematic analysis was employed, and interpretation of findings was guided by the Socio-Ecological Model and Transtheoretical Model, to examine changes in behavior and context over time. Participants were classified as either sustainers or non-sustainers based on their overall behavioral trajectory.ResultsFive overarching themes were identified: (1) From avoidance to approach; (2) Becoming an independent exerciser; (3) Establishing a new routine; (4) Outsourcing willpower; (5) Evidence of self-determined behavior. Individual-level factors such as confidence, motivation, and acceptance of pain were central to sustained engagement, but these were shaped by broader influences including access to facilities and social support.ConclusionSustained physical activity following rehabilitation is a dynamic, context-dependent process. Interventions should prepare individuals for independent physical activity by fostering the development of psychological and self-regulatory skills, whilst also considering community and policy-level influences. Incorporating these elements may enhance sustained engagement in structured physical activity and improve long-term rehabilitation outcomes.