Researchers: later school start times offer big bang for the buck

Kyla Wahlstrom, Director of the Center for Applied Research and Educational Improvement (CAREI) in the College of Education and Human Development at the University of Minnesota

It's something that takes every parent of an incoming middle school child by surprise.

After years of leisurely mornings in K through 5, we send teenagers to class one to two hours earlier than most of us are expected to be at the office.

Like the majority of school districts in the state of Minnesota, most public middle and high school classes start at 7:40 a.m. in Rochester, with buses picking up children as early as 6:30 a.m. Not exactly baker's hours, but according to researchers, not good for kids' grades, health or safety, either.

In fact, if school policy was guided by medical science, Rochester Public Schools would have delayed middle and high school start times to 8:30 a.m. a long time ago.

"It's research that arose in the late 1980s and early 1990s, says Kyla Wahlstrom, director of the Center for Applied Research and Educational Improvement at the University of Minnesota. "At that time, it was brand new medical information that had come out about the brain development of teenagers. It has to do with the final maturation of the brain itself."


One of the biological effects of puberty, she explains, is a sleep cycle shift driven by a change in the timing of the brain hormone melatonin. During teen years, the brains of adolescents will not release the sleep-triggering hormone until later in the evening — 10:45 or later — a process that  continues until 8 in the morning. "They find this true of all teens in the world," says Wahlstrom. "It's a human being phenomenon, not just an American cultural thing. It's relatively new in medical knowledge."

Making 'different kids'

Since then, Wahlstrom has researched the benefits for children attending schools that shift to later start times. After the Edina Public Schools made the change from in 1996 and Minneapolis schools in 1997, she learned, not only did kids not stay up any later, "the teachers told me 'I can't get over it, these are different kids,'" she recalls. Most of the Edina school district parents she surveyed agreed. "They loved it," she says. "They said, 'I can talk to my kids in the morning.'"

Writing in the journal Preventive Medicine in 2011, Centers for Disease Control researchers reported that getting less than eight hours of sleep was associated with higher odds of cigarette, marijuana, and alcohol use, as well as sexual activity, fighting and lack of sustained physical inactivity. These were associations, but last year, Wahlstrom co-authored the largest study ever conducted of the before-and-after effects on children in schools who delay start times.

Her February 2014 study looked at 9,000 students, in eight school districts, in three states, for three years. It found that schools starting at 8:35 a.m. or later allowed 60 percent of kids to get eight hours of sleep, versus 30 to 50 percent of children who started at 7:30 a.m. She found that teens who don't get eight hours of sleep faced higher depression symptoms and were at greater risk of substance use. Teens who switched to 8:35 or later start times improved their grades in core subject areas like math, English, science and social studies. In one school, the shift to later start times reduced car crashes by 70 percent, from 23 to 7.

In September, the American Academy of Pediatrics came out in support of later school start times, stating that "the evidence strongly implicates earlier school start times (i.e. before 8:30 a.m.) as a key modifiable contributor to insufficient sleep" in teenagers. The statement added that "a substantial body of research has now demonstrated that delaying school start times...has a wide range of potential benefits to students with regard to physical and mental health, safety, and academic achievement."

"I think the later start times could be beneficial," says Dr. Jane Rosenman, an assistant professor of pediatrics at Mayo. Rosenman says the negative impacts of late night screen use on sleep quality make the change even more reasonable. "Sleep is something that we can have a say in. There are so many benefits of sleep and so many things that can be negatively altered by lack of sleep, from mental health to attention span in school to attention span while driving."

Hard decisions


School policy has been slow to follow. Minneapolis, Edina, Alexandria and a few dozen other school districts have pushed back start times (St. Paul is considering it), but it remains a minority in the state's 325 school districts. "I am a school policy researcher," said Wahlstrom, "so I know how hard these decisions are."

Critics point to the cost: The same school buses used to deliver teenagers are needed to deliver elementary children two hours later. Switching elementary children to early start times has been proposed as a solution, but as researchers in Kentucky found last year, elementary school children also fare worse with early start times. In schools she has studied, Wahlstrom says buying new buses has not been necessary.

"There are ways to use the existing buses at no extra costs," she said. "You just have to revamp how you use them." These include multi-age school buses, "hub-and-spoke" busing systems, and distributing passes for high school kids to use the city buses, a solution adopted in Minneapolis.

Parents worry that extending the school day will cut into sports, but in Edina, Wahlstrom learned, coaches shortened practices by 20 minutes and found the athletes more focused and productive.

Other arguments against come down to parental convenience — the desire to have an older sibling at home before younger siblings return. 

Rochester Public Schools did not return requests for comment on the question of delayed start times.

School Board member Deborah Seelinger said she thinks the change is possible, but says the district needs time for parents to weigh in on it.

"I think most people feel like it's a good idea," she said,, "but we get stuck with the implementation.


"I think what's keeping the conversation alive for me," Seelinger said, "is if we know this is best practice, if we know this is what's good for kids, how can we keep the conversation going and not just say, 'No, we've never done that so we aren't going to to do that.'" 

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