Physical Activity and Sedentary Time as Key Moderators in the Stress-Quality of Life Relationship Among the Older Adults

Background: Stress is one of the important factors influencing the quality of life (QoL) among older adults. However, the buffering and exacerbating factors influencing this relationship remain unclear. This study aimed to investigate the moderating effects of physical activity and sedentary behavior on the relationship between stress and quality of life (QoL) in elderly living in low- and middle-income countries. Methods: This cross-sectional study analyzed data from 7,905 adults aged > 60 years in the WHO Study on Global Ageing and Adult Health (SAGE) across five developing countries (China, Ghana, India, the Russian Federation, and South Africa). Stress, QoL, physical activity, sedentary behavior, and sociodemographic variables were assessed through standardized questionnaires. Hierarchical regression models and PROCESS moderation analyses were conducted to examine whether physical activity and sedentary time moderated the relationship between stress and QoL. Results: Higher stress levels were significantly associated with lower QoL (p< .001). Physical activity positively predicted QoL, while sedentary time showed a negative association. Moderation analyses indicated that physical activity attenuated the negative impact of stress on QoL, whereas prolonged sedentary time exacerbated this effect. The combined model revealed that high physical activity levels and limited sedentary time exerted a significant moderating influence on the impact of stress determinants of on QoL. Conclusions: The findings suggest that physical activity and sedentary behavior play significant moderating roles in the stress-QoL relationship among older adults. Engaging in regular physical activity and reducing prolonged sedentary time may serve as effective strategies for stress and QoL managements in aging populations.