Changes in Sleep Quality, Depressive Symptoms, and Sleep-Wake Preference Among University Students Participating in an Eight-Week Evening Aerobic Exercise Program: A Quasi-Experimental Study.

Background/Objectives: Sleep disorders and depressive symptoms are common among college students and can negatively impact quality of life. Physical activity is recommended as a non-pharmacological approach to support sleep and mental health; however, findings regarding regular evening aerobic exercise in young adults are limited. This study aimed to examine changes in sleep quality, depressive symptoms and sleep-wake preferences among university students participating in an eight-week evening aerobic exercise program. Methods: This quasi-experimental study included 51 university students who were assessed before and after an eight-week intervention. Participants engaged in 60 min of aerobic exercise three days a week in the evening (between 6:00 PM and 10:00 PM). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), depressive symptoms using the Beck Depression Inventory (BDI), and morning-evening type using the Morning-Evening Questionnaire (MEQ). Results: At the end of the eight-week period, a significant improvement was observed in total PSQI scores; significant changes were also noted in the subscales of sleep onset latency, habitual sleep efficiency, sleep disturbances, and daytime dysfunction (p < 0.05). A significant decrease was observed in BDI scores (median: from 17 to 9; p < 0.001), and the proportion of students with moderate-to-severe depressive symptoms decreased. A significant increase was also observed in MEQ scores (p < 0.001), which was found to be consistent with a shift toward an earlier sleep-wake preference. Conclusions: While these findings suggest that an eight-week evening aerobic exercise program may offer potential benefits in improving sleep quality and reducing depressive symptoms among university students, it is thought that changes in sleep-wake preferences may reflect short-term behavioral adaptation.