By Alan Mozes
WEDNESDAY, Dec. 12, 2018 (HealthDay News) -- Would delaying the start of school help sleep-deprived teens get more of the shut-eye they need?
Yes, suggests a Seattle experiment that assessed how adolescent sleep habits changed after the opening school bell shifted from 7:50 a.m. to 8:45 a.m.
The result: high school students ended up clocking an extra 34 minutes of sleep per night, on average. Better yet, that was accompanied by a 4.5 percent average rise in grades.
"Around 90 percent of adolescents are not getting the recommended 8 to 10 hours of daily sleep," said study author Horacio de la Iglesia, a professor of biology at the University of Washington in Seattle.
"[But] we found that after the Seattle school district delayed the start time of secondary schools from 7:50 to 8:45, the students gained 35 minutes of daily sleep, felt less sleepy, improved their grades, and in a school with high representation of lower-income students they also increased their attendance and punctuality," he added.
Two teachers who had students involved in the experiments couldn't agree more.
Cynthia Jatul, a teacher at Roosevelt High School in Seattle, described the results of the later start time move as "encouraging," and said the change ultimately produced "students who are more awake and engaged in morning classes.
"I see less first-period tardiness," she added, "and far fewer students sleeping in class."
Roosevelt colleague Tracy Landboe agreed. "The difference in the attention and energy level of my students during the morning as compared to the earlier start is 'night and day,'" she said.
What's more, the benefits are apparent even outside the classroom, Jatul noted, pointing out that "parents have also reported marked improvement in student mood, which they appreciate because family dynamics suffer when students are constantly sleep-deprived."
The nearly one-hour delay in school start times was implemented during the 2016-2017 academic year, and affected a total of 18 Seattle high schools.
To explore the impact, investigators focused on a pool of students drawn from Seattle's Roosevelt High School and Franklin High School.