Increasing Physical Activity in Pediatric Heart Transplant Recipients: Insights from Patients and Their Families to Inform Intervention Design and Implementation

Background Survival after pediatric heart transplantation (HT) remains limited, and recipients face a heightened burden of modifiable cardiovascular risk factors. Despite the well-established benefits of physical activity (PA), pediatric HT recipients demonstrate reduced exercise capacity and low participation in moderate-to-vigorous physical activity (MVPA). Effective interventions require a nuanced understanding of behavioral determinants influencing PA engagement. This study sought to characterize perceived barriers, facilitators, and intervention preferences among pediatric HT recipients and their caregivers using the Capability–Opportunity–Motivation Behavior (COM-B) framework. Methods We conducted semi-structured interviews with pediatric HT recipients aged 6–22 years and their caregivers at a single tertiary transplant center. Participants were purposively sampled to ensure variation in age at transplant, diagnosis, time since transplant, and prior exposure to PA interventions. Interviews explored current activity patterns, perceived barriers and facilitators, and preferences for structured exercise programs. Transcripts were analyzed using an integrated thematic approach combining a priori COM-B constructs with inductively derived themes. Results Thirty-four interviews were completed with 17 caregiver–patient dyads and one independent adult participant. Participants generally viewed PA as safe, enjoyable, and emotionally beneficial, reflecting strong intrinsic motivation and preserved psychological capability. Social influences—including peers, family members, and opportunities to connect with other transplant recipients—emerged as powerful motivators for sustained engagement. In contrast, logistical factors such as transportation, scheduling conflicts, and distance from the transplant center were the most frequently cited barriers, highlighting limitations in physical opportunity rather than medical constraints. Caregivers emphasized the importance of professional oversight to enhance confidence, while patients and caregivers identified goal setting and progress tracking as key motivational supports. Many participants favored home-based or virtually delivered interventions to improve accessibility. Conclusions Pediatric HT recipients appear both willing and capable of participating in physical activity; however, sustained engagement is largely determined by opportunity and social motivation rather than physiologic limitations. Interventions that prioritize accessibility, incorporate peer connection, and provide structured feedback may promote durable behavior change. These findings offer a theory-informed foundation for designing scalable PA interventions aimed at improving long-term cardiovascular health in pediatric HT recipients.