Background <p>Frail older adults undergoing cardiac surgery are at increased risk of functional decline. As part of developing a follow-up program, Nantes University Hospital selected Vivifrail, a structured, multicomponent exercise program designed to improve strength, balance, and mobility. This study aimed to evaluate the barriers and drivers conducive to the adoption of Vivifrail among frail older patients who had recently undergone cardiac surgery.</p> Methods <p>We performed a qualitative study using semi-structured interviews between March and December 2024. Eligible patients had recently undergone cardiac surgery in Nantes University Hospital, were aged 75&#xa0;years and older, with a baseline SPPB score &lt; 9. Patients were interviewed between weeks 5 and 6 post-discharge. Interview transcripts were analyzed using reflexive thematic analysis.</p> Results <p>Among 27 eligible patients, 23 were interviewed. The first 9 interviews were conducted using a preliminary version of the guide in order to help us enrich the final version. To ensure methodological rigor and limit interpretation bias, only interviews conducted with the final guide were included in the analysis. As a result, data from 14 interviews were analyzed until data saturation was reached. The average age of participants was 79 years old (± 4), and 71% were men. Median SPPB scores varied between 7 [6–8] points at baseline and 10.5 [9–11] points post-intervention. Three main themes emerged from the interviews. First, patients frequently described post-operative challenges such as impaired physical condition, discomfort, and fatigue. Second, despite these difficulties, the vast majority (11 of 14) demonstrated moderate to strong adherence. Upon returning home, the Vivifrail program served as a framework for patients to start physical activity. The support of healthcare professionals and family also appeared to be decisive. Third, most patients (11 of 14) reported adapting their physical activty according to the recovery of their abilities, particularly through performing activities of daily living, drawing on personal and environmental resources.</p> Conclusions <p>The Vivifrail program is a promising approach for guiding frail older adults who have recently undergone cardiac surgery towards establishing a regular physical activity routine. Given the exploratory and qualitative nature of our study, our findings are not representative of the entire frail older population but may be transferable to other similar patients in comparable care settings.</p> Trial registration <p>Clinical trial number not applicable. The study was approved by the Nantes Health Ethics Group (GNEDS), Nantes, France (N°24–22-02–273), and registered on OSF: <a href="https://doi.org/10.17605/OSF.IO/7HTX2">https://doi.org/10.17605/OSF.IO/7HTX2</a></p>