Later School Start Times Associated with Better Sleep and Academic Performance

Research on the impact of later school start times on sleep hygiene and academic performance among middle school students is limited by small samples. Investigators took advantage of variable school start times in a large middle school district (165,000 students) to evaluate potential associations. Three cohorts of eighth grade students (33,000 total; 50% female, 42% white) self-reported how much sleep they got on weeknights, their grades, and their academic effort (“How often do you finish your homework?”). School start times were categorized as earliest (7:20–7:30 a.m.), early (7:40–7:55 a.m.), and latest (8:00–8:10 a.m.).

Students could report sleep duration of as little as <4 to as much as ≥9 hours. The probability of getting A's was hig…