For young children and teenagers, not getting enough sleep can have bad effects, such as irritability, stress, learning problems, and low motivation. But a recent study shows that afternoon naps are a great way of avoiding these negative impacts.
The study, published in the journal Sleep, charted the afternoon nap habits of 3,819 elementary school children in China. The children, who were followed over a period of several years, were between 10 and 12 years old; most previous research had focused on younger children.
The researchers measured the kids’ weekly nap frequency and duration, and also collected information about their behavioral and academic achievement. In addition, the researchers asked the children to answer questions about their self-assessed levels of grit, self-control, and happiness. Some of the children also took IQ tests, and physical exams measured the kids’ body mass index and glucose levels.
More afternoon naps = more benefits
The study found that afternoon naps correlate significantly with more happiness, more grit, more self-control, higher verbal IQs, and better academic achievement. And the longer the average nap duration, the greater the benefits.
The strongest findings were associated with academic achievement, said co-author Adrian Raine: “Children who napped three or more times per week benefit from a 7.6% increase in academic performance in Grade 6,” he said.
Sleep deficiency and daytime sleepiness affect up to 20% of all children, said lead author Jianghong Liu.
In the United States, napping is not a common feature in elementary school. But in China, afternoon naps continue all the way up to high school.
The researchers say that introducing daytime naps to U.S. schools might be a novel way of addressing the growing push for later school start times. Daytime naps would also be a much simpler intervention than rescheduling the entire school day.
Polyphasic sleep and biphasic sleep
Napping is a form of “polyphasic sleep,” which means sleeping at varying times in a given day. The most common type is “biphasic sleep”, which usually consists of a nighttime segment and a daytime segment.
The finding that biphasic sleep happens independently of the cycles of light and dark dates back more than a century, when biologists discovered that two-hour sleep phases often alternate with long periods of wakefulness.
According to some reports, biphasic sleep can be beneficial when it occurs during the day, as it helps an individual increase their alertness. It can also improve concentration and attention, and potentially help with creative and analytical thinking.
Although such habits may seem convenient, having an extremely fragmented sleep schedule can leave a person feeling fatigued, with less than the full sleep cycle. It can also prevent a person from achieving the total amount of sleep they need. And biphasic sleep can be detrimental for night owls, as it makes it more difficult for them to fall asleep at night.
Afternoon naps for kids
The average person gets between six and eight hours of sleep a night, but kids need more.
For kids, afternoon naps are not just a luxury. In fact, afternoon naps are a healthy and necessary part of a child’s healthy sleep cycle. Sleep deficiency can cause a number of health problems, including high blood pressure, depression, and obesity. Afternoon naps enable a quick recharge when children are at their most tired in the daytime.
A good rule of thumb is that at the beginning of the day, young children should have short, 30-minute naps and a longer nap of up to an hour and a half at the end of the day.
And of course: afternoon naps are good for kids because they allow you to rest, too.
Study: “Midday napping in children: associations between nap frequency and duration across cognitive, positive psychological well-being, behavioral, and metabolic health outcomes,” doi.org/10.1093/sleep/zsz126 (link)
Authors: Jianghong Liu, Rui Feng, Xiaopeng Ji, Naixue Cui, Adrian Raine, Sara C Mednick
Published in: Sleep, Volume 42, Issue 9, September 2019
Photo: by Civalias Kune on Unsplash