Physical activity and quality of life--the complementary influence of self-efficacy for physical activity and mental health difficulties.

Background: Studies proposed that the physical activity and quality of life (QoL) relationship may not be entirely direct but mediated through other variables; however, few studies have examined these relationships in diverse population's older adults.

Purpose: This study aims to examine the roles of self-efficacy and mental health difficulties in the physical activity and QoL relationship and to determine if demographic characteristics alter these relationships.

Methods: One hundred ninety-six older adults completed measures of physical activity, self-efficacy, mental health difficulties, and QoL. Two-multilevel structural models were tested to determine the relationship between physical activity and QoL.

Results: Both structural models suggested that the relationship between physical activity and QoL is indirect, but the models were not significantly different. In model 1, we observed a positive linear relationship between physical activity and self-efficacy. In turn, self-efficacy was negatively associated with poor mental health difficulties and positively associated with QoL. Mental health difficulties were also negatively associated with QoL. In model 2, physical activity was positively associated with self-efficacy and negatively associated with mental health difficulties; in turn, self-efficacy was positively associated with QoL, whereas mental health difficulties were negatively associated with QoL.

Conclusions: Overall, our findings suggest that self-efficacy and mental health have intermediary roles in the relationship between physical activity and QoL in a diverse sample of older adults. Prospective studies are needed to determine whether self-efficacy and mental health difficulties are complementary or one or the other accounts for more variance in the relationship between physical activity and QoL.