Later school start times for high school students appear to have a beneficial effect on their sleep habits, according to a study released by National Jewish Health.
The study began in 2017 when the Cherry Creek School District (CCSD) Board of Education voted to change start times.
That fall, high schools in CCSD moved from a 7:10 a.m. to 8:20 a.m. start time. Middle schools moved from an average of 8 a.m. to 8:50 a.m. To accommodate bus schedules, elementary schools moved earlier, from a 9 a.m. start time to around 8 a.m.
Over the course of the study, researchers found the teenagers got more sleep — around 30 minutes each night for middle school students and 45 minutes for high school students.
“We looked at daytime sleepiness and found that significantly fewer students were reporting being sleepy during the daytime,” said Dr. Lisa Meltzer, professor of pediatrics at National Jewish Health.
Meltzer said students reported being more alert and participating more in their first period class.
Meanwhile, the elementary students were able to go to bed earlier, and only lost about 11 minutes of sleep each night on average. Meltzer said for older kids, it’s not as easy to go to bed earlier.
“When kids go through puberty, the timing of sleep changes. It's a biological change where your internal clock gets delayed by about an hour or two,” Meltzer said.
Meltzer said other districts, including Denver Public Schools, JeffCo Public Schools and the Douglas County School District have looked into reversing start times for elementary and secondary students. She said there are ways that allow teens to get more sleep without disrupting afternoon sports or after school jobs.
“They can’t be successful in high school if they’re not getting enough sleep, and we know that if you're not getting good grades and graduating and having good mental health in high school, that is not setting you up for success in the real world,” Meltzer said.
National Jewish Health is currently conducting a study looking into how sleep habits changed for students who learned remotely during the pandemic.