Better sleep is associated with higher academic performance from an actigraphy-based analysis of sleep consistency and grades in college students

Academic performance is influenced by sleep; however, the relationship between academic outcomes and subjective sleep measures remains controversial. This study aimed to evaluate the association between sleep parameters and academic performance using objective actigraphy measurements alongside subjective assessments. University students (n = 33) enrolled in a sleep psychology course participated in the study and completed all assessments. Participants completed three subjective questionnaires and 14 consecutive days of actigraphy recordings. They were retrospectively divided into high- and low-performing groups based on the median final exam score. Four objective sleep parameters derived from actigraphy were analyzed: sleep efficiency (SE), sleep onset latency (SOL), wake after sleep onset, and total sleep time (TST). Additionally, the mean absolute deviation (MAD) was introduced to assess night-to-night variability in these parameters. Results showed no significant group differences or correlations between subjective sleep measures and academic performance. In contrast, students with higher exam scores exhibited significantly greater SE, shorter SOL, and lower MADs for SE, SOL, and TST. Final exam scores were significantly associated with SE, SOL, and the MADs of SE, SOL, and TST. These associations were especially pronounced on weekdays, where exam scores correlated with SE, SOL, and the MADs of SE and SOL. Our findings highlight the importance of consistent, high-quality sleep during weekdays for academic success. Furthermore, this study contributes novel insights into the predictive value of night-to-night variability (MAD) in sleep parameters for academic performance. Overall, the results underscore the critical role of stable and efficient weekday sleep in supporting positive academic outcomes.