Sleep medicineMay 21, 2016

How School Start Times Affect Sleep Patterns in Children and Teens

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗

Updated Mar 31, 2026

Abstract

A total of 639 students aged 8 to 18 participated in the study, revealing significant sleep deficits associated with school start times.

Students with morning school schedules showed higher age, greater differences in bedtimes and wake-up times, and increased sleep deficits.
Girls experienced a greater sleep deficit compared to boys of the same age, with significant differences in weekday and weekend wake-up times.
Sleep deficit is positively correlated with age and differences in wake-up times, while negatively correlated with morningness-eveningness scores and social jetlag.
Significant predictors of sleep deficit include social jetlag, differences between weekday and weekend waking times, and the midpoint of sleep on weekends.

Simplified

OBJECTIVE: This epidemiological study evaluated the impact of school time on sleep parameters of children and adolescents.

METHODS: This cross-sectional study involved 639 elementary and high school students (mean age 13.03 years, range 8-18, 58.5% female) from the south of Brazil. Participants answered the Morningness-Eveningness Questionnaire (MEQ), and were asked about their sleeping habits on weekdays and weekends. Sleep deficit was defined as the difference between sleep duration on weekdays and weekends.

RESULTS: The morning-school-time students presented significantly higher age, bedtime and wake up differences, sleep deficits, and social jetlag. The sleep deficit presented by girls was greater than that observed in boys of the same age. The difference between weekday and weekend waking times was also significantly greater in girls than in boys aged 13-18 years. Sleep deficit was significantly positively correlated with age and differences in wake up times, and significantly negatively correlated with MEQ scores, social jetlag, difference between weekday and weekend bedtimes, midpoint of sleep on weekends, and midpoint of sleep on weekends corrected for sleep deficit. A step-by-step multivariate logistic regression identified social jetlag, the difference between waking times on weekdays and weekends, and the midpoint of sleep on weekends as significant predictors of sleep deficit (Adjusted R(2) = 0.95; F = 1606.87; p <0.001).

CONCLUSION: The results showed that school time influences the sleep parameters. The association of school schedules and physiological factors influence the sleep/wake cycle.

Full Text

Full text is available at the source.

View Full Text ↗

How School Start Times Affect Sleep Patterns in Children and Teens

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief