 The study investigates the association between long working hours and health by defining it as working time greater than 40 hours per week or 8 hours per day, minimizing the influence of shift work and emphasizing the importance of reference groups. The results show that long working hours have significant adverse effects on most health outcomes, including depressive state, anxiety, sleep condition, and coronary heart disease. However, further studies are needed to appropriately address the definition of long working hours and shift work. This article was authored by Akira Benai and Akiko Tamakoshi.