Abstract
BACKGROUND: The wear and tear from chronic stress exposure has been linked to premature aging through allostatic load; however, it is unclear how chronic stress exposure affects physical functioning and physical activity in older adults. OBJECTIVES: The study aims were to examine the behavioral and functional adaptation to chronic stress in older adults and its mediational pathways. METHODS: Data from the Health and Retirement Study 2016 and 2020 ( N = 3075, mean age 66 years) were analyzed. Chronic and perceived stress exposure was quantified using Troxel's Chronic Stressors Scale and Cohen's Perceived Stress Scale. Physical activity was quantified using self-reported questionnaires, including light, moderate, and vigorous physical activity. Physical functioning was operated as a latent construct with four perceived physical limitations (i.e., difficulty in movement, hand strength, shortness of breath, and balance). The cross-sectional data were analyzed using latent regression analysis. The longitudinal data were analyzed using serial mediation based on MacKinnon's bias-corrected bootstrap confidence intervals. RESULTS: Cross-sectionally, psychological stress, as a latent construct indicated by stress exposure and stress perception, explained more variances in perceived physical limitation than physical activity. Longitudinally, perceived stress and physical activity mediated the relationship between chronic stress exposure and perceived physical limitation with significant indirect effects. Furthermore, perceived physical limitation suppressed the effect of chronic stress exposure on physical activity levels. The effects of mediation and suppression remained significant after the adjustment for age, gender, years of education, race, number of comorbidities, working status, and marital status. DISCUSSION: The promotion of physical activity and physical functioning in older adults might not achieve the optimal outcome if the program design overlooks the target population's chronic stress process and functional limitations.