Studying the impact of later school start times

Teens have a biological preference to fall asleep later than younger children and adults, and wake up later, due to a delayed release of hormones that promote sleep. This timing coincides with puberty and makes it harder for middle and high school students to fall asleep early – regardless of 5 a.m. alarms and 7:17 a.m. school start times.

After studying this trend among nearly 1,000 seventh and eighth-grade students in 11 middle schools within a Mid-Atlantic school district, Daniel Lewin, Ph.D., a sleep medicine specialist, pediatric psychologist and associate director of the sleep medicine program at Children’s National Health System, coauthored and published research entitled “Later Start, Longer Sleep: Implications of Middle School Start Times” in the Journal of School Health, which outlines the benefits of delaying school start times.

The research team divided students into two groups: Close to 650 students attended eight late-starting middle schools, where school started at 8 a.m., while nearly 350 students attended early-starting middle schools, where school started at 7:23 a.m.

Students starting school 37 minutes later, despite going to bed 15 minutes later than peers attending an earlier-starting school, got 17 minutes more sleep each night and were more likely to report feeling wide awake during class. The researchers predicted this later-starting school model would translate to students getting an extra 75 minutes of sleep a week – roughly 51 hours of extra sleep each school year. These researchers find that every two minutes in delayed school start times results in one minute of additional sleep each night for children and teens.

The American Academy of Pediatrics (AAP) published similar research in their journal, Pediatrics, about the benefits of letting teens catch up on sleep, citing a reduced risk of students being overweight, getting into car accidents or suffering from depression as well as a greater likelihood of having better grades, higher test scores and a better quality of life. AAP recommends schools start at 8:30 a.m. or later to allow students to get 8.5 to 9.5 hours of sleep each night and issued a statement in 2014, entitled “School Start Times for Adolescents.”

Dr. Lewin continues to track these benefits and works with schools to implement the changes. He recently wrote an editorial, entitled “All the Clocks Are Ticking: Sleep Health and Metabolism,” for the Journal of Adolescent Health about the correlation between improved sleep health, mental and physical health and academic performance, explaining how circadian clocks, present on a cellular level, influence behavior and metabolism.

While pushing school start times back requires an immediate investment of rearranging travel routes, bell schedules and after-school activities, several school districts near Washington, D.C., from Virginia Beach to Fairfax County, are adopting this public health model.

An economic analysis conducted by the RAND Corporation finds that after two years, the benefits of reorganizing school start times outweigh the costs.