Most teens start school too early in the morning, which deprives them of the sleep they need to learn and stay healthy, a new study says.
The American Academy of Pediatrics last year urged middle schools and high schools to start no earlier than 8:30 a.m. in order to allow teens — who are biologically programmed to stay up later at night than adults — to get the recommended 8.5 to 9.5 hours of sleep each night.
But 83% of schools do start before 8:30 a.m., according to a study released Thursday by the Centers for Disease Control and Prevention. The average start time for 39,700 public middle schools, high schools and combined schools was 8:03 a.m., based on data from the 2011-2012 school year.
School systems have debated whether to delay school start times for years. Many parents have asked schools to start later, arguing that their teens have trouble waking up early enough to get to school by 7:30 a.m., let alone learn.
“It makes absolutely no sense,” said physician M. Safwan Badr, a past president of the American Academy of Sleep Medicine. “You’re asking kids to learn math at a time their brains are not even awake.”
But many school officials have argued that starting class later would make it more difficult to schedule after-school sporting events, which often require teams to take buses to other parts of their districts.
“It’s a logistical nightmare,” said Daniel Domenech, executive director of AASA, the School Superintendents Association., who said that school districts have to consider the cost of school buses, as well as traffic and after-school activity schedules.
Allowing high schoolers to sleep in could mean sending elementary kids to school in the dark during the winter, as they would have to take the early schedule. That could pose a safety dangers to the youngest kids as they walk to school or wait at bus stops, Domenech said.
Starting high school later also would mean starting sports practices later and make it more difficult for teens to get to after-school jobs, Domenech said.
He notes that early school start times are nothing new.
“This has been going on forever, and kids have been graduating from school and going on to college,” Domenech said. “It certainly doesn’t seem to have hurt them all these years.”
Yet studies show that today’s teens are chronically sleep deprived, said Judith Owens, director of sleep medicine at Boston Children’s Hospital and lead author of the pediatric academy report.
Two-thirds of high school students today fail to get even eight hours of sleep on school nights, according to the CDC report. Adolescents who don’t get enough sleep are at higher risk for being overweight, depressed and using tobacco, alcohol or illegal drugs, but less likely to get enough exercise, according to the CDC. Over time, people who don’t get enough sleep are more likely to develop heart disease and type 2 diabetes, Owens said.
“This is a major public health issue,” said Badr, noting that parents should consider sleep to be as important for a child’s health as nutrition and exercise. He encourages parents to be firm with kids, setting bed times and telling teens to shut off their electronic devices.
Sleep deprivation also can lead to drowsy driving and car accidents, Owens said.
Studies on driving simulators show that “not getting enough sleep at night is the equivalent of consuming three or four beers and being moderately intoxicated,” Owens said. “So teens are getting behind the wheel as impaired as if they had consumed a fair amount of alcohol.”
Owens notes that students who finish school in the early afternoon spend more time unsupervised, giving them more time to get into trouble before their parents arrive home from work.
While some adults assume that sleepy teens are lazy, Badr said that adolescents’ natural sleep cycles are very different than adults’.
While the average adult’s body tells her to sleep from about 11 p.m. to 6:30 a.m., the typical teen body wants to sleep from about 12 a.m. or 1 a.m. until 8 a.m. or 9 a.m., Badr said. When school starts too early, “they’re waking up at a time when their brain doesn’t want them to be awake.”
Kids forced to wake up too early also miss out on REM sleep, which is important for consolidating memories and helping people to remember what they learned that day, Owens said. REM sleep tends to be concentrated in the last third of the night, or between 6 a.m. and 9 a.m. for a typical teen, Badr said.
“It’s like telling you that you have to get up at 3 o’clock in the morning and function at full capacity,” Owens said.
Some schools have made changes aimed at improving teen sleep.
Owens has worked with the public school system in Fairfax County, Va., where high school used to begin at 7:20 a.m., and the first buses began picking kids up as early as 5:45 a.m. This fall, high school will begin at 8:10 a.m. Researchers are collecting data to see if the later start time leads to any changes in test scores or health, including the number of kids who report being depressed or who are injured playing sports, Owens said.
