Evaluating an Expanded Health Action Process Approach Model of Health Promotion to Predict Physical Activity Levels of Individuals With Chronic Health Conditions and Disabilities

Physical activity is associated with reduced stress, anxiety, and depression. This study evaluated autonomous motivation and social support for exercise in addition to the Health Action Process Approach (HAPA) model as predictors of physical activity among people with chronic health conditions and disabilities. This is secondary data analysis. Participants were 982 U.S. individuals with chronic health conditions and disabilities. Hierarchical regression analysis (HRA) was used to assess variable impact sequentially, and a serial multiple mediation analysis (SMMA) was utilized to test mediation effect. The HAPA model constructs, autonomous motivation, and social support for exercise accounted for 35% of the variance in physical activity scores, a large effect size. Commitment was the strongest predictor, followed by autonomous motivation and self-efficacy. SMMA results indicated that autonomous motivation was associated with self-efficacy and commitment, and these factors were significantly associated with physical activity. Self-efficacy and commitment significantly mediated the relationship between autonomous motivation and physical activity. Autonomous motivation thus plays an important role in predicting the physical activity levels of adults with disabilities, warranting the inclusion of an autonomy construct in the HAPA model.