Differential exercise effects on quality of life and health-related quality of life in older adults: a randomized controlled trial

Purpose: Maintaining quality of life (QOL) and physical and mental health status are important outcomes throughout the aging process. Although cross-sectional studies suggest a relationship between global QOL and physical activity, it is unclear whether such a relationship exists as a function of exercise training. Methods: We examined the effects of two exercise intervention arms on health-related quality of life (HRQOL) and global QOL. Low-active, older adults (n = 179) were randomly assigned to either a 12-month aerobic walking group or a strengthening and flexibility group. HRQOL and QOL were measured at baseline, 6, and 12 months. Results: There was a significant group by time effect on QOL [F(2,176) = 3.11, p = 0.047, η² = 0.03]. There was also a significant overall group by time effect for HRQOL [F(4,174) = 2.46, p = 0.047, η² = 0.05], which was explained by the significant group by time interaction for mental health status (p = 0.041, η² = 0.02) favoring the walking condition. Further analyses using latent class analysis revealed three classes of individuals with differential patterns of change in QOL and HRQOL across time. These classes reflected no change, declines, and improvements in these constructs across time. Conclusions: Walking appears to enhance the mental aspect of HRQOL and global QOL when compared to a non-aerobic intervention. Additionally, the patterns of change in QOL and HRQOL were not linear over time. Our findings are in contrast to previous reports that these outcomes change a little or not at all in randomized trials.