Promoting central competencies for health-enhancing physical activity in individuals with multiple sclerosis. Findings from a secondary data analysis across a cross-sectional study and a randomized controlled trial

Introduction To identify physical activity-related health competence (PAHCO) elements associated with physical activity (PA) volume and health in persons with multiple sclerosis (pwMS), and to examine whether these elements can be modified through a competence-oriented PA intervention. Materials and methods Secondary analyses combined data from a cross-sectional survey and a randomized controlled waitlist trial. Structural equation modeling identified PAHCO elements associated with PA volume and health among 475 pwMS. Intervention effects on these elements were examined using repeated-measures multivariate analysis of variance. PwMS who were clinically stable and met digital participation requirements were randomized ( N = 56) to a 12-week digital, competence-oriented PA intervention (IG) or usual care (CG). Results “Manageability of endurance demands”, “body awareness”, “affect regulation”, and “PA-specific self-control” showed the strongest associations with PA volume and health. Compared with the CG, the intervention improved “manageability of endurance demands” and “PA-specific self-control” (analytical sample: IG = 24; CG = 26) in the IG, while “affect regulation” showed a non-significant trend favoring the IG. Conclusions A competence-oriented PA intervention improved two of four PAHCO elements relevant to PA volume and health in pwMS. These findings support targeting specific PAHCO elements as potential active ingredients of PA promotion interventions in pwMS. Clinical Trial Registration https://clinicaltrials.gov/ , identifier NCT04367389.