Effects of a randomized exercise trial on physical activity, psychological distress and quality of life in older adults

Objective: Evidence suggests improvements in positive psychological health indices (e.g., self-esteem) may explain the relationship between physical activity and quality of life (QoL) in older adults. Less is known about the role of reductions in negative psychological health indices (e.g., depression). The present study examined the effects of changes in moderate-to-vigorous physical activity (MVPA) and psychological distress on change in QoL in older adults enrolled in an exercise program. Methods: Older adults (N = 247, Mage = 65.68 +/- 4.59) participated in a six-month randomized exercise trial. Participants wore accelerometers and completed questionnaires to measure MVPA, psychological health, and QoL at baseline and post-intervention. Psychological distress was modeled as a latent factor comprised of anxiety, depression, sleep dysfunction, and stress. Structural models were used to examine the effects of changes in MVPA and distress on change in QoL. Results: Increases in MVPA predicted reductions in distress from baseline to post-intervention (B = -0.10, p = 0.05). In turn, reductions in distress predicted increases in QoL (B = -0.51, p = 0.001). The indirect effect of MVPA on QoL through distress was also significant (p = 0.05; 90% CI = 0.005, 0.125). Conclusions: Findings extend previous research on the mediators of the MVPA-QoL relationship in older adults, suggesting reductions in negative psychological health outcomes may also mediate this pathway.