High School Students See Higher Grades, Fewer Absences With Later Start Times

SEATTLE — If you’re convinced the push for a later start to school times in many districts across the country in recent years will cause more of a strain on parents’ work schedules and less of a benefit to their kids, some new research could change your mind. A new study finds that children not only log healthier levels of sleep, they also perform at a higher level in the classroom when they begin the school day slightly later.

After the Seattle Public School District followed the recommendation of the American Academy of Pediatrics and delayed their school start time by 55 minutes (from 7:50 am to 8:45 am), researchers from the University of Washington decided to study the effects on teenagers and their academic performance.

The data reveals better sleep cycles, better attendance, and better grades for high school students.

Research has suggested that delayed school start times give teenagers a better chance to stay within their natural sleep schedules and are more likely to excel school. To put it another way, the authors compare having to be at school by 7:30 a.m. for children to an adult having to clock-in at the office at 5:30 a.m.. Promoters of the delayed start-times believe a change would narrow the gap between high- and low-achievers.

“All of the studies of adolescent sleep patterns in the United States are showing that the time at which teens generally fall asleep is biologically determined — but the time at which they wake up is socially determined,” explains lead researcher Gideon Dunster, a doctoral student in biology at the university, in a release. “This has severe consequences for health and well-being, because disrupted circadian rhythms can adversely affect digestion, heart rate, body temperature, immune system function, attention span and mental health.”

Dunster and his team studied two Seattle high schools, Franklin High School in the South End, and Roosevelt High School in Ballard. The team measured the sleep-wake cycles of sophomores in both schools using wrist-worn activity devices. A group of 92 students wore the high-tech wristbands every day for two weeks in the spring of 2016, when start times were still at 7:50. Then in 2017, seven months after classes were pushed to 8:45, another group of 88 students were tasked with wearing the monitors.

The delayed start times produced measurable results. Students experienced an increase in sleep time by 34 minutes on average (totaling seven hours and 24 minutes each night), which led to a 4.5 percent increase in final grades.

“Thirty-four minutes of extra sleep each night is a huge impact to see from a single intervention,” says senior and corresponding author Horacio de la Iglesia, a professor of biology at the university.

What’s more, attendance at Franklin, located in a low-income neighborhood, increased dramatically, while tardiness dropped. The more affluent Roosevelt High School saw no difference in attendance after the delayed start times went into effect.

“This study shows a significant improvement in the sleep duration of students — all by delaying school start times so that they’re more in line with the natural wake-up times of adolescents,” says de la Iglesia.

The American Academy of Pediatrics recommended in 2014 that school days for middle and high school students begin no earlier than 8:30 a.m., but most U.S. high schools still start before then. The authors hope their research will help lead to greater change.

The study was published December 12, 2018 in the journal Science Advances.

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