Barriers to and Facilitators of Physical Activity in X-Linked Hypophosphatemia: Insights from Lived Experiences

X-linked hypophosphatemia (XLH) is a hereditary phosphate-wasting disorder that progressively impairs mobility, physical functioning and quality of life. Although physical activity (PA) can improve physical functioning for common comorbidities of XLH, such as osteoarthritis, its effects in individuals with XLH are not understood. The objective of our study was to understand how XLH impacts the experience of participating in PA and to identify barriers to and facilitators of PA specific to people with XLH. To complete our objective, we conducted semi-structured qualitative interviews with adults diagnosed with XLH. Data was analyzed using reflexive thematic analysis. 17 adults (2 male) participated, and we identified four main themes: (1) people living with XLH are unable to or are uncomfortable participating in impact exercise; (2) excessive physical activity causes fatigue and exacerbates pain and stiffness; (3) exercise as a tool to improve symptoms of XLH and function in the long term; (4) strategizing movement and tailoring exercise is essential to exercise participation. We identify two potential intervention directions leveraging identified facilitators to address the reported barriers: (1) education on pacing designed to help individuals with XLH manage fatigue and pain; (2) a continuing education resource designed to help exercise providers tailor exercise for individuals with XLH. Future research should focus on understanding PA in XLH to inform the development of feasible and appropriate interventions. In addition, improving understanding of the pathophysiology of consequences such as osteomalacia, OA, and enthesopathies may help clarify risks associated with PA and XLH.