Later School Start Times Means More Sleep, Better Grades for Adolescents

Later school start times have been recommended for adolescents for several years now by the American Medical Association (AMA). A recent study suggests the AMA was right all along: middle and high school students with later school start times get more sleep. Maybe the extra sleep is the reason they’re also less likely to be too sleepy to do their homework.

The Cherry Creek School District of Greenwood Village, Colorado, began offering later school start times in 2017. The switch afforded researchers a golden opportunity to study the before and after effects of delaying school start times on student well-being and school performance. Middle schools delayed start times by 50 minutes, changing from 8 AM to 8:50 AM. High schools delayed start times by 70 minutes, changing from 7:10 AM to 8:20 AM.

The study found that one year after later school start times were put into effect, students in middle school said they were sleeping 31 minutes longer. The high school students said they were sleeping 48 minutes longer.

Internal Clock

“Biological changes in the circadian rhythm, or internal clock, during puberty prevents teens from falling asleep early enough to get sufficient sleep when faced with early school start times,” said lead author of the study Lisa J. Meltzer, Ph.D., an associate professor of pediatrics at National Jewish Health in Denver, Colorado. “This study provides additional support that delaying middle and high school start times results in increased sleep duration for adolescents due to later wake times.”

In addition to the AMA recommendation that schools implement later school start times, the American Academy of Sleep Medicine (AASM) recommends that middle schools and high schools start at 8:30 AM. The AASM says this is something teens need to keep them healthy, alert, and safe. An earlier analysis by the Centers for Disease Control and Prevention (CDC), however, found that only 19% of middle schools begin at 8:30 AM or later, while only 14% of high schools do so. It seems that schools are having trouble adapting to the idea. It’s also not so easy to cram all that learning into a later time frame that may not end with teachers getting home in time to have dinner with their families.

The Cherry Creek study included over 15,000 students in grades 6-11. Students completed online surveys before and after school start times were delayed. Questions on the survey touched on weekday and weekend bedtimes, wake times, and total sleep time. Kids also answered questions about sleepiness levels while doing homework and about how engaged they were with their studies and in the classroom.

More Engagement

The percentage of students who said they were too sleepy to do their homework dropped after school start times were delayed. In the middle school students, the number of kids too sleepy to do homework changed from 46% to 35%. Before the delay, 71% of high school students said they were too sleepy to do homework. After the later school start time was implemented, that number dropped to 56%. Kids also reported they were more engaged in their studies, paying more attention in class, after the later school start time began. This greater classroom engagement was reported by both middle and high school students.

“The study findings are important because getting enough sleep is critical for adolescent development, physical health, mood, and academic success,” said Meltzer.

Superintendent of the Cherry Creek School District, Dr. Scott Siegfried, said that the study backs up everything the students have told him about later school start times in this 108-square-mile school district.

“I don’t know how many of our high school students have come up to me and said, ‘This has changed my life for the better.’ They’ve told me they’re getting up to an hour of additional sleep before school starts,” Siegfried remarked. “That extra sleep makes a real difference in terms of health and wellness. The input from our students and the numbers from this landmark study point to the same conclusion: The change in our start times has been a positive step and benefited our students’ everyday routines.”

Later School Start Times Good For Teachers, Too

This particular research abstract was published in an online supplement of the journal Sleep and is to be presented Wednesday, June 12, in San Antonio at SLEEP 2019, the 33rd annual meeting of the Associated Professional Sleep Societies LLC (APSS), a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. But it’s not the only research abstract to come out of this study. Meltzer has authored a second abstract entitled, “Impact of Changing School Start Times on Teachers/Staff.” That study found that later school start times offered significant benefits to middle and high school teachers and school staff. The subjects said they slept longer and improved daytime functioning as a result of later wake times.

Meltzer says this was the first large study to examine the impact of later school start times on teachers and staff. “It is important to consider that this policy change, critical for the health and well-being of students, also impacts other members of the school community,” said Meltzer.

Found what you just read useful? Why not consider sending a donation to our Kars4Kids youth and educational programs. Or help us just by sharing!

Found what you just read useful? Why not consider sending a donation to our Kars4Kids youth and educational programs. Or help us just by sharing!

Subscribe via email

About Varda Epstein

Varda Meyers Epstein serves as editor in chief of Kars4Kids Parenting. A native of Pittsburgh, Pennsylvania, Varda is the mother of 12 children and is also a grandmother of 12. Her work has been published in The Washington Post, The Huffington Post, The Learning Site, The eLearning Site, and Internet4Classrooms.