Han's study [50] confirmed that a middle-aged
adult who made use of sports facilities to enjoy sports had a higher quality of life than a person who did not. Through the study by Giannouli et al., [49] the researchers verified that exercise was closely connected with a middle-aged woman's quality of life. In Lee and Choi's study [51]; the researchers proved that a middle- aged adult whose cognition degree of stress had a higher quality of life. From all these findings, we summarized that if a middle-aged person was younger, had a higher education level, a higher monthly income, a more stable occupation, no disease, less stress, and exercised, the person would show a higher quality of life. Therefore, for adults in middle age who are going through physical, psychological, and socioeconomic changes in their life, it is essential that research investigate the deterrent factors that prevent them from enjoying high quality of life and plan preventative strategies in order to prepare them for their elderly life.