Predictors of Physical Activity Enjoyment in Adults with Cystic Fibrosis: The Role of Quality of Life and Motivation-A Single-Center Study.

Despite the well-documented physical and psychological benefits of regular physical activity (PA) and exercise, participation remains insufficient in adults with cystic fibrosis (pwCF). In the general population, PA enjoyment is a key determinant of sustained engagement, yet its predictors in CF populations remain underexplored. We aimed to examine associations between clinical parameters, health-related quality of life (HRQoL), motivation and PA enjoyment in adult pwCF. We hypothesised that higher intrinsic motivation and better HRQoL would predict greater enjoyment, independent of clinical parameters. In this cross-sectional study, 197 adult pwCF (mean age = 36.6 ± 11.9 years) from a single centre completed validated questionnaires assessing PA and exercise enjoyment (Physical Activity Enjoyment Scale, PACES), motivation (Behavioral Regulation in Exercise Questionnaire-2, BREQ-2), and HRQoL (Cystic Fibrosis Questionnaire-Revised, CFQ-R). Hierarchical regression was conducted in three steps: clinical variables (Model 1), added HRQoL domains (Model 2), and motivational variables (Model 3). : The complete model explained 68.4% of the variance in PA and exercise enjoyment (R = 0.684, < 0.001). Intrinsic motivation was the strongest positive predictor (β = 6.228, < 0.001), while external regulation negatively predicted enjoyment (β = -1.932, = 0.030). Among HRQoL domains, only health perception remained significant (β = 0.081, = 0.038). Clinical variables alone accounted for minimal variance (R = 0.023, = 0.370). Intrinsic motivation was the most robust predictor of PA and exercise enjoyment, outweighing clinical and most HRQoL factors. These findings support autonomy-supportive strategies to foster internal motivation and enhance long-term PA and exercise participation in adult pwCF.