Too early for teens

High school students often roll out of bed with the roosters so they can pack in a full day of school, sports and homework. But that early start could be hindering their performance by slashing their sleep cycle and by forcing them to work when they are at their wooziest, suggests a new study.

“Most standardized tests are given at 8 a.m., when performance is at its worst,” says Martha Hansen, a biology teacher at Evanston Township High School in Illinois who led the study. “That’s something we can start lobbying to change right away.”

Hansen tested 61 of her senior biology students to see how their reaction time varied during the school day. She found that reaction times were much slower in the morning than in the afternoon. Students also kept sleep journals during summer vacation and the school year. Teens slept an average of two hours less during the school week than on the weekend because they had to get up earlier. Summertime sleep patterns resembled weekend sleep patterns, suggesting students revert back to their natural sleep cycle on weekends, Hansen says.

“A lot of parents think teenagers are being lazy when they sleep late on the weekends,” she says. “It might help them to know that [teens] are doing what they’re genetically programmed to do.”

The project was a collaboration between students, teachers and parents at Evanston Township High School and scientists at Northwestern University in Chicago and was published in the June issue of Pediatrics.