Determinants of Quality of Life in Older Adults: The Role of Sarcopenia, Physical Fitness, and Lifestyle Factors

To examine the relationship between the applicability of the Sarcopenia & Quality of Life (SarQoL) questionnaire and physical fitness factors including living environment, body composition, and exercise function of individuals aged over 60 years were analyzed. The study included 551 older adults (129 men, 422 women) aged 60–100 years, residing in South Korea, and without serious diseases, disabilities, or physical activity limitations. Demographics, health indicators, living conditions, SarQoL survey results, and physical fitness were assessed. Group differences were evaluated using one-way ANOVA with Tukey’s post hoc test. Hierarchical regression analysis explored the relationship between SarQoL scores and various factors, and multiple logistic regression analyzed the association between SarQoL and exercise variables. Statistical significance was set at <i>p</i> < 0.05. Sex (B, 0.200; t, 2.233; <i>p</i> < 0.001), age (B, −0.031; t, −6.574; <i>p</i> < 0.001), education level (B, −0.110; t, 3.067; <i>p</i> = 0.002), and regular physical activity influenced SarQoL scores. Physical fitness measures were significantly correlated with SarQoL scores. Additionally, conditions such as diabetes, sleep disorders, and sarcopenia affected SarQoL outcomes. High SarQoL in older adults is associated with higher educational attainment, presence of medical conditions, and improved physical fitness. This underscores the complex interplay of physical and mental health in the aging process and highlights the importance of preventing and managing sarcopenia to improve the quality of life for older adults.