Research shows that teens' natural sleep cycle is to sleep later in the morning. Some schools are responding by pushing back start times.
Ringing the School Bell Later
Teens have long felt that the school day starts too early: A 2007 survey of teens in Philadelphia found that most students believed a 7:30 a.m. start time at school prevented them from getting enough sleep. Ninety percent of the students surveyed felt that if school started later, their academic performance would improve. They also said the best time for them to be taking exams would be between 11 a.m. and 1 p.m.
New research seems to substantiate their claims. According to Marissa Cevallos, writing for the San Jose Mercury News, puberty affects sleep cycles. "When teens hit puberty, their internal circadian clocks wind forward 1-3 hours, meaning they need 9 hours of sleep on average, a couple more hours than their younger siblings."
Several schools in California and around the United States and Britain have listened. In the U.S., 19 states have adjusted start times for certain schools to be later in the day, and 17 more states are looking in to the practice. The goal is to help teens get more sleep.
A Minneapolis school district that has made the later start adjustment seems to be seeing the benefits. Kyla Wahlstrom, an educational researcher, found that students were less depressed, easier for their parents to deal with, and more attentive to their teachers with a later start time, according to NPR. She also reported that with a later start time, fewer students dropped out of school.
Later school start times might have one positive and unpredicted effect on teens: a lower car crash rate. A Kansas school district adjusted start times to be an hour later; a study of the teen car crash rates before and after the adjustment found a significant drop in the number of auto accidents for teens in that county.
Opinion: Do teens need a late start or more parenting?
Jim Horne, the director of the Sleep Research Center at the Loughborough University, thinks the later starts might just mean more time spent with friends or on the computer. "It's possible this [lack of sleep] could be solved with better parental control," he told the Associated Press.
But other researchers disagree. Richard Schwab of the University of Pennsylvania says that teens have a different circadian rhythm than adults, and that the natural bedtime for teens is between midnight and 1:00 a.m. "If school start times were based on sleep cycles," Schwab told ScienceDaily, "elementary schools should start at 7:30 and high schools at 8:30 or 8:45 - right now it is the reverse."
KidsHealth explains that the change in the circadian rhythm has to do with what time the hormone melatonin is produced. Adults produce this hormone earlier in the day than teens, who produce it later at night and then have a harder time falling asleep.
At least according to one study, teens seem to be using later start times to get more sleep. Researchers in Connecticut found that a delayed start time of 40 minutes resulted in an average increase of sleep by 33 minutes. According to ScienceDaily, one author of the study, Mary B. O'Malley, said that this demonstrated that "students given the opportunity to sleep longer, will, rather than extend their wake activities on school nights."
Reference: How much sleep is enough?
Teens need about nine hours of sleep each night. To learn more about the sleep requirements for children, teens, adults and seniors, along with ways to help prevent sleep disorders and improve overall sleep quality, visit the findingDulcinea Sleep Web Guide.