Timetable naps into the school day for teenagers, study suggests
Naps should be timetabled for secondary school children, a study by the University of Delaware suggests.
Researchers studied the link between a post-lunch sleep and brain function in early adolescents.
They found that youngsters who napped five to seven days in a week had sustained attention, better nonverbal reasoning ability and spatial memory.
The best amount of time to nap for was found to be between 30 and 60 minutes, but the researchers said not to nap after 4pm.
The researchers were also surprised to find that people who napped more often tended to have better night time sleep.
The study was conducted on 363 youngsters, with an average age of 12, in China where mid-day napping is common. The researchers measured midday napping, nighttime sleep duration and sleep quality, and performance on multiple neurocognitive tasks.
Study leader Xiaopeng Ji said: "Daytime napping is quite controversial in the United States. In Western culture, the monophasic sleep pattern is considered a marker of brain maturation.
"In China, time for napping is built into the post-lunch schedule for many adults in work settings and students at schools."
Ji has studied the natural sleep and wake pattern of cells, known as the circadian rhythm. A shift in this rhythm takes place during adolescence, with teenagers naturally wanting to wake up an hour or two later than younger children.
"Think about that in a school schedule," Ji said. "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."
The findings are published in the journal Behavioural Sleep Medicine.