Difference in subjective sleep quality and related lifestyle habits of student-athletes according to chronotype: a cross-sectional study.

Abstract

Background: Sleep plays a vital role in the recovery of athletes, yet many student-athletes struggle with poor sleep quality. The literature has reported that chronotypes, which reflect different circadian phases, are related to poor sleep quality and lifestyle habits. However, there is a lack of findings specific to student-athletes. This study aimed to investigate differences in subjective sleep quality and related lifestyle habits among student-athletes based on their chronotype.

Methods: Student-athletes were defined as university athletic club members. A cross-sectional web-based survey collected data from 665 student-athletes at three Japanese universities (male: 70.7%; mean age: 19.7 ± 0.8 years). Chronotypes were assessed using the Morningness-Eveningness Questionnaire, while subjective sleep quality was measured using the Pittsburgh Sleep Quality Index. Lifestyle habits included skipping breakfast, taking caffeinated drinks, using a smartphone/cellphone after lights out, and morning practice. Subjective sleep quality and these lifestyle habits were compared among chronotypes using one-way analysis of covariance (ANCOVA), along with binomial and ordinal logistic regression analyses, adjusted for sex and age.

Results: The chronotype distribution was 15.9% eveningness, 72.9% intermediate, and 11.1% morningness. Individuals with later chronotypes had a higher prevalence of poor sleep quality. Additionally, a higher percentage of those with later chronotypes skipped breakfast and used a smartphone/cellphone after lights out. A lower percentage of later chronotypes also participated in morning practice ≥ 4 days/week. However, morning practice ≥ 4 days/week was associated with poor subjective sleep quality only among student-athletes with an evening chronotype, not among those with intermediate or morning chronotype.

Conclusion: Addressing poor lifestyle habits and promoting earlier chronotypes may be crucial for improving subjective sleep quality in student-athletes with an evening chronotype.