OBJECTIVE: To evaluate post-transcatheter aortic valve replacement (TAVR) physical activity and explore the factors influencing participation. DESIGN: A quantitatively driven sequential explanatory mixed-methods study was performed from October 2021 to February 2022 in Shanghai, China. PATIENTS: The study sample comprised 195 patients who underwent TAVR (58.46% men, mean age = 74.38 years. METHODS: A cross-sectional survey was conducted to assess the extent of physical activity maintenance after TAVR via the International Physical Activity Questionnaire-Short Form (IPAQ-SF). Preliminary factors were identified via Poisson regression. Subsequently, Fogg's behaviour model-guided targeted qualitative interviews were conducted to confirm and expand on barriers and facilitators to physical activity engagement. RESULTS: 93.33% of post-TAVR patients lacked regular physical activity. Fourteen barriers and facilitators were identified and grouped into motivation (health expectation, social belonging, feeling after physical activity, kinesiophobia), ability (complex forms of physical activity, misperceptions, scheduling conflicts, traffic and distance, self-regulation), and triggers (surroundings and environment, peer and family support, professional support, mobile health, internalization of exercise habits). CONCLUSION: The study findings indicate low adherence to regular physical activity among patients post-TAVR. Intervention strategies that increase patients' motivation and ability to perform physical activity and provide appropriate triggers should be further developed.