Gender effects on theory-based psychosocial predictors of increased physical activity, and its subsequent influences on relations of fatigue with other psychosocial factors within Parkinson disease physical activity classes
BACKGROUND: Physical activity is considered useful for individuals with Parkinson disease. Its effects on psychosocial factors, and gender differences have been understudied in those affected, and require additional investigation. METHODS: Existing participants of community-based Parkinson disease physical activity classes (22 men, 19 women, age M=71.1 years) were assessed on changes in exercise-related self-efficacy, mood, self-regulating physical activity, task-related social cohesion, internal health locus of control, and levels of physical activity from the time they initiated class, to the present (average length of participation ~13 months). RESULTS: There were no gender differences at baseline and, with the exception of internal health locus of control, each factor significantly improved, overall. There was a significant gender × time relationship indicting greater improvement in exercise self-efficacy in the women. Multiple regression analyses indicated that changes in exercise self-efficacy, total mood disturbance, and self-regulating physical activity significantly predicted physical activity change (R2=0.45). The addition of changes in social cohesion and internal health locus of control into step 2 of that equation did not increase the explained variance in physical activity change. Relations of physical activity change with changes in the dimensions of depression, tension, anger, confusion, but not vigor, were significantly mediated by change in fatigue. Gender differences were minimal, overall. CONCLUSIONS: The physical activity classes were associated with significant improvements in mood and other quality-of-life factors. Findings suggest that physical activity-induced changes in fatigue serve as a conduit to changes in other dimensions of mood, including depression.