DAVID GREENE, HOST:
There's a movement to make sure kids aren't sleepless in Seattle. With homework, extracurriculars, kids aren't getting enough sleep. Seattle's solution? Start school later. Here's NPR's Patti Neighmond.
PATTI NEIGHMOND, BYLINE: Seattle schools pushed back the opening bell for all high schools and most middle schools by about an hour, from 7:50 in the morning to 8:45. Researchers at the University of Washington wanted to know if that resulted in more sleep. The answer? Yes - 34 more minutes. Lead researcher Gideon Dunster.
GIDEON DUNSTER: Thirty-four minutes may not sound like a lot to the average person, but for those of us who study in this field, this is a huge impact, beneficial impact for the students.
NEIGHMOND: Fewer students were absent from class. Fewer were late. And overall, grades increased by 4.5 percent.
DUNSTER: That can be the difference between an A or a B, between passing a class and not passing a class.
NEIGHMOND: Students wore Fitbit-type wrist devices which measured light and activity levels so researchers knew when students were awake or asleep. They compared students in a 10th-grade biology class when school started early to students in that same biology class when school started later. Teachers saw a big difference. Roosevelt High School biology teacher Cindy Jatul says once school started later, there was a lot less yawning and a lot more focus.
CINDY JATUL: I'm constantly, as a lab teacher, interacting with students and asking them to explain things that they're doing and interpret data, et cetera. And well-rested students are much more capable of engaging and analyzing and articulating what they're learning.
NEIGHMOND: And if you're wondering why kids just don't go to bed earlier, senior author Horacio de la Iglesia says once children reach puberty, their biological clock changes.
HORACIO DE LA IGLESIA: You can send them to sleep, but they will lay in bed and they will not fall asleep. They will not be able to biologically fall asleep until midnight, at least.
NEIGHMOND: The American Academy of Pediatrics recommends all schools start at 8:30, but only a handful of counties nationwide are doing that. Patti Neighmond, NPR News.