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A Long Winter'S NAP

Less than 20 years ago, discoveries about teen sleep began changing school start times in Minnesota. Now it’s a national movement.

Kyla Wahlstrom
Kyla Wahlstrom

One morning in 1996, Kyla Wahlstrom got a call from a local superintendent. His school board had just decided to change the high school start time from 7:15 to 8:30 the next fall, only months away. Emerging research on profound differences in teen sleep patterns was so strong that the board believed a later start time could help their students. The superintendent called Wahlstrom because she directs the U’s Center for Applied Research and Educational Improvement (CAREI), which examines new things happening in schools.

Wahlstrom admits she was skeptical. But Edina went through with the plan and the results astounded everyone. A year later, all seven high schools in Minneapolis followed suit. CAREI was asked to investigate and report the findings. Now, 15 years later, as author of the School Start Time Study, Wahlstrom is called upon by school districts across the country that are considering the change.

Here are Wahlstrom’s answers to some common questions.

How is teen sleep different than sleep for anybody else?

Sleepiness is caused by melatonin’s release in the body, which is regulated by the central nervous system. Medical research shows that teenagers—different from young children and adults—have a distinct sleeping and waking cycle. Almost all teens in the world, not just in our country, tend to fall asleep biologically about 10:45 p.m., and their bodies and brains want to stay in the sleep mode until about 8 in the morning. The shift in sleep timing happens at puberty, around age 13, and lasts until about age 19. That’s still more than nine hours of sleep a teen needs every night.

Younger children need 10 to 12 hours of sleep, and they can easily fall asleep at a regular bedtime that is very early. Of course the body is also regulated by sunlight, so kids are naturally more ready to stay up in the summer when the sun is still up, too.

Then as adults, we go back to our genetically determined sleep patterns and need less sleep—usually around 8 hours. About 22 percent of us are larks and wake up naturally very early in the morning, around 5 to 6 a.m., and about 27 percent of us are owls, who naturally don’t feel sleepy until 1 or 2 a.m. and don’t function well until around 10 a.m. The rest of us are somewhere in the middle.

What difference does it make to change school start times?

In the initial findings in both Edina and Minneapolis the teachers said, “This is a different bunch of kids now with the later start. They are awake and ready for learning.” And the principals said, “We have a different school here!” There were fewer disruptions in the lunchroom, and passing times in the hallways were more subdued. School counselors said the students were self-referring less for peer relationship problems. When we interviewed parents—and we interviewed and surveyed hundreds of parents—they said their kids were easier to live with. Of course, it makes sense—no matter how young or old we are, we’re less crabby when we get enough sleep!

Up Next

In October 2013, the Twin Cities will host a major national conference on teen sleep—the intersection between medicine, education, and policy—cosponsored by CAREI and the U’s Academic Health Center. Child psychologists, pediatricians, school personnel, and policymakers are just some of those expected to attend. Watch for conference information on the CAREI website.

After five years, Minneapolis found a statistically significant improvement in the graduation rate. Kids stopped missing the bus and missing as much class time. In 2010, a study in Virginia showed a connection between later start times and a drop in car accidents by teens on their way to school in the morning. So there are tremendous positive outcomes by pushing back start times for high schools by at least an hour.

How many schools have changed?

We stopped counting when more than 250 schools across the country had made the change. In Minnesota, it appears that many school districts have shifted to at least 8 a.m., and more are considering an 8:30 start. It’s happening everywhere—I’ve heard from every state in the union. Just today I had a call from a national newspaper to check some facts for an article they’re running about the local issues that districts have in making such a change.

Are there costs and problems?

It can be very difficult for schools historically starting at 7:15 or 7:20 to make that shift. But Minneapolis did it, with 52,000 enrolled students at the time they made the move, at no cost. What we’ve seen is that it requires two things—a lot of careful planning, and for people to believe the facts. By now the medical link between teen sleep and school performance is strong.

Making the change creates an imbalance in the community for about a year. You know: When are buses on the road? When are babysitters available? In school districts where they use the same set of buses for all grade levels, like Minneapolis, it means the elementary students are now waiting for the bus on those winter mornings in the dark. It’s a real concern. Some neighbors take turns waiting with the kids in the morning. On the other hand, those little ones may not be going home in the dark at the end of the day anymore.

What can parents do to help teens get enough sleep?

It’s about routines—the human body really likes routines. The body has to slow down to get ready to fall asleep. Even as adults we know we can’t come home from a party and jump in bed! So parents can establish routines for their kids to slow down before bed. There’s also brand-new research about the effect of light that comes off all of our devices—cell phones and computers and TV: it’s very disruptive to the brain because the brain thinks it’s daylight. It’s a different wavelength than regular light bulbs. So a half hour before bedtime, depending on your kids’ ages, you can say shut everything off except a lamp. They can have a quiet game or story—parents can read to younger ones, or kids can read themselves something calming in bed.

And we can tell them why! Sleep is important for learning.

How does sleep affect learning?

The function of sleep is to “prune” our memories of the stimuli that have bombarded us all day and to consolidate what’s important. If you don’t have that pruning and consolidation, you wake up all scattered and disorganized. This is true for human learning at any age—information is consolidated in your brain during sleep, especially REM sleep. A good night’s sleep is all about learning.

Learn more about CAREI, the direct research link between CEHD and Minnesota schools preK-16, and school start-time research.

Story by Gayla Marty | Winter 2013



This article first appeared in Connect, the magazine of the College of Education and Human Development.
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