By Julie Dahl, APRN, CNP, President of the MN Sleep Society, Respiratory Consultants; Julie Baughn, MD, Mayo Center for Sleep Medicine, Children’s Center; Robin Lloyd, MD, Mayo Center for Sleep Medicine, Children’s Center
It is widely known that adequate sleep is required for optimal health and learning. Yet, adolescents nationwide are sleep deprived. Why? As children transition to adolescence, their biological sleep clocks shift, with a delay in melatonin release occurring around 10:45 pm (1). With early school start times, adolescents are unable to get the quality, well-timed sleep they need. In Minnesota, 87 percent of high schools start before 8:30 a.m. and 60 percent of adolescents report inadequate sleep (2,3). Parents will likely turn to their pediatricians for the facts.
Clear evidence: Later school start times are healthier for adolescents
Parents like Renee Leinbach confirm their teenagers are exhausted despite limit-setting. “Her phone is left downstairs at 9 pm and lights out at 10:30 pm. But then she lays there, unable to fall asleep. It’s beyond frustrating.” Adolescents are forced to wake before their brains are ready and many are in a constant state of jet-lag. Consequences include poor academic performance (4) and an increased risk of mental health issues, already prevalent during adolescence including drug use, depression and suicide. (5,6) There is also a 1.7 times greater risk of sport related injury and negative affects on athletic performance with decreased reaction time and more errors in the setting of sleep loss (7,8).
When school start times are later, total sleep time significantly increases for adolescents (9,10), which leads to less tardiness, fewer school absences and improved outcomes in core classes like math and reading (11-13,20). (see Table #1) The gains more sleep provided were even stronger for at-risk students (14). One study showed delaying start times could even give a boost to the US economy by increasing school performance and potential for lifetime earnings (15).
Safety and health benefits are also achieved with later start times. Evidence shows fewer car accidents involving adolescents in communities where start times are changed, with one study showing a 16.5 percent drop in the average crash rate (16, 17). Later school start times, even by about 30 minutes, can lead to less risk-taking behavior and an improved mood (18-20). Coaches at schools with later start times report better performance and decision making as athletes remember plays better.
Alex Malm, a St. Paul student was able to start school later his senior year, “I could wake up on my own and I wasn’t falling asleep in classes. I was in a better mood and had much more energy for athletics and homework.”
Community disruption is temporary, health benefits for adolescents are long-lasting
There are logistical factors when adjusting start times including busing, athletic schedules and childcare. To keep transportation costs neutral, some districts will have the elementary schools start first. There is some rationale to this strategy as younger children have more malleable sleep schedules and are wired to wake up earlier than adolescents, a fact not lost on elementary teachers. Core curriculum classes like math and reading are often held during the first part of the day for this reason and many of these teachers prefer school to start earlier (see Table #2).
There are only a handful of articles on the effects on elementary students and school start time. Some reveal elementary age students can still obtain adequate sleep and there is no difference in academic performance from an early-start school compared to a later-start school (21,22). Others suggest academic performance and behavior may be affected (23,24). Currently there is not enough data to determine “how early is too early” for younger students. This lack of data does not justify ignoring the decades worth of research showing adolescents benefit from more sleep.
Schools in 45 states have been able to work through barriers and come up with solutions. They have shown both later start times and after-school activities can coexist successfully. Many families who required after school care were able to adjust work schedules or find less expensive childcare by enlisting the help of grandparents or neighbors. The majority of the fears and concerns people expected before the start time was adjusted, found the actual scheduled change to be much less problematic and the benefit to students in these districts will be appreciated by future generations of students to come.
Informing stakeholders about the facts
Pediatricians are in a perfect position to educate parents and adolescents that sleep, like activity and nutrition, is a pillar of health and is critical for short- and long-term health benefits. Stress healthy sleep habits by minimizing caffeine use, avoiding screen time before bed, keeping a regular sleep schedule and steering clear of drowsy driving.
Those of us in sleep medicine, along with primary care providers and school health professionals ask for your support to inform communities, school boards and legislators to follow the policy recommendation from your national organization (25) and others, including the AMA and the AASM (26,27) calling for middle and high schools start times of 8:30 am or later.
A well-rested child is a healthy child who can meet their full potential in school and beyond. So one key point to keep in mind as you review this body of evidence is the unbending nature of biology. Adolescent sleep schedules are never going to change. School start times can.
2. Minnesota Student Survey 2016: 85% of schools in the state participated, data pull by MN Sleep Society, Retrieved from www.mnsleep.net
10. Morgenthaler TI, Hashmi S, Croft JB, Dort L, Heald JL, Mullington J. High school start times and the impact on high school students: what we know, and what we hope to learn. J Clin Sleep Med 2016;12(12):1681–1689.
13. Hysing M, Harvey AG, Linton SJ, Askeland KG, Sivertsen B. (2016). Sleep and academic performance in later adolescence: results from a large population-based study. Journal of Sleep Research 25(3):318–324.
22. Dupuis, D. (2015). The Association Between Elementary School Start Time and Students’ Academic Achievement in Wayzata Public Schools. University of Minnesota. Center for Applied Research and Educational Improvement. Retrieved from the University of Minnesota Digital Conservancy,
23. Keller, P Earlier School Start Times as a Risk Factor for Poor School Performance: An Examination of Public Elementary Schools in the Commonwealth of Kentucky Journal of Educational Psychology, 2015:107(1):236-245
25. American Academy of Pediatrics, Adolescent Sleep Working Group, Committee on Adolescence and Council on School Health. (2014). School start times for adolescents. Pediatrics. doi: 10.1542/peds.2014-1697
26. AMA Supports Delayed School Start Times to Improve Adolescent Wellness. Press release: Jun 14, 2016. Retrieved from /www.ama-assn.org/ama-supports-delayed-school-start-times-improve-adolescent-wellness.
27. Watson NF, Martin JL, Wise MS, Carden KA, Kirsch DB, Kristo DA, Malhotra RK, Olson EJ, Ramar K, Rosen IM, Rowley JA, Weaver TE, Chervin RD. Delaying middle school and high school start times promotes student health and performance: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2017;13(4):623–625.