It’s an afternoon class and most of the pupils are trying to fight off drowsiness — an experience most people perhaps can identify with.
When students at Meizen High School in Kurume, Fukuoka Prefecture, start to get the nods, they do what comes naturally, and later wake up more alert.
Naohisa Uchimura, an assistant professor of neuropsychiatry at Kurume University in the prefecture, conducted a 40-day experiment at the high school in June and July to study the effects of taking a siesta in the middle of the school day.
According to his findings, 127, or about 61 percent, of 208 students who took 15-minute naps — between 1:15 and 1:30 p.m. — at least once a week said they were able to concentrate better during their afternoon classes. This compares with 274 out of 595 students — roughly 46 percent — who did not take a nap.
Uchimura observed a similar trend when he questioned the students about whether their academic performance and emotional state improved with the naps.
“This (study) shows that just a 15-minute nap (after lunch) can help students focus and stabilizes their mental health,” he said.
The idea that naps refresh the mind and body is nothing new, with many businesses offering places for employees who want to take siestas.
In a report released in 2003, the Health, Labor and Welfare Ministry recommended that people take 20- to 30-minute naps before 3 p.m., saying it would help keep them healthy and improve work efficiency.
Uchimura’s findings show the positive effects of napping found in adults are the same for high school students.
The average amount of sleep high school students get at night has become significantly shorter in recent decades.
Teens are staying up later to chat on the phone with friends, to exchange e-mail, to go to cram schools or watch videos and DVDs, according to the researcher.
He said the average amount of sleep during the week that 2,429 students at eight high schools in Kurume got last year was six hours and one minute, about one hour less than 20 years ago.
Uchimura said that lack of sleep can make high school students emotionally unstable and lead to a decline in their ability to think.
“When it’s impossible to prolong their night sleeping time, a 15-minute midday nap can help them form a positive attitude toward everyday life,” he reckoned.
To ensure quiet for the after lunch nap, Meizen prepared five quiet classrooms and had Mozart music added.
But a special environment is not necessary. Even people who cannot nap can benefit from just closing their eyes and relaxing for five minutes, according to Uchimura.
However, he warned that sleeping for more than 30 minutes during the day could have the opposite effect of making someone less alert.