Should Teens Be Allowed to Nap in School?

By Jane Farrell

Teens get into trouble for falling asleep in school, but they’d probably perform better if they were allowed to take a scheduled nap, researchers say.

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In a study funded by the National Institutes of Health, the University of Delaware’s School of Nursing assistant professor ‘s Xiaopeng Ji and principal investigator Jianghong Liu (University of Pennsylvania) turned to the Chinese classroom for comparison. With participants from schools in Jintan, Ji measured midday napping, nighttime sleep duration and sleep quality, and performance on multiple neurocognitive tasks.

Neurocognitive functioning is essential for learning, emotion and behavior control.

The study’s findings suggest an association between habitual midday napping and neurocognitive function.

“Daytime napping is quite controversial in the United States,” Ji said. “In China, time for napping is built into the post-lunch schedule for many adults in work settings and students at schools.”

According to a news release from the University of Delaware, Ji has studied the circadian rhythm of sleep (a person’s 24-hour cycle). A developmental change takes place in circadian rhythm during adolescence; teenagers’ rhythm shifts one to two hours later than the preadolescent period.

“This phase delay is biologically driven in adolescents,” Ji said. “Think about that in a school schedule. Teenagers have to get up early for school. And, with this phase delay of going to bed later, they are at-risk for chronic sleep deprivation.”

Ji explained that these adolescents may experience impaired neurocognitive function, which makes paying attention in school even more difficult. Memory and reasoning ability also suffer.

A circadian dip occurs daily from 12 to 2 p.m. During that period, adolescents are more likely to fall asleep. In a U.S. school, a student does not have a formal opportunity to do so.

“Throughout childhood, U.S. kids experience decreases in napping tendencies. Kids are trained to remove their midday napping behavior,” said Ji.

There is a great deal of literature on adults and sleep, but that’s not the case for adolescents. And since the American school schedule was a barrier to finding more information about the link between midday napping and neurocognitive function, researchers used Chinese data in the study.

Ji investigated two dimensions of nap behavior — frequency and duration.

The conclusion: Routine nappers, who napped five to seven days in a week, had sustained attention, better nonverbal reasoning ability and spatial memory.

As for how long a nap should be, Ji concluded that the best length is between 30 and 60 minutes. Participants who slept between 30 to 60 minutes produced better accuracy in attention tasks as well as faster speed.

The researchers were surprised to find a positive relationship between midday napping and nighttime sleep. Habitual nappers (who napped more often) tended to have a better nighttime sleep, they found.

“That’s different than the findings in the United States, where napping may serve as a function to replace sleep lost from the previous night. Consequently, that may interfere with the following night’s sleep,” Ji said. “In China, a midday nap is considered a healthy lifestyle. Routine nappers are more likely to experience healthy nighttime sleep. So routine nappers are essentially trained to sleep well and sleep more at night.”

Ji said that further studies might help influence public policy in the U.S.