A Chinese research team has found that teens could be a risk of chronic sleep deprivation.
A Western way of shunning daytime naps could be impacting teens sleep, according to a new observational study.
Xiaopeng Ji, a Chinese researcher studied individual’s 24-hour sleep cycle. In adolescents, they found that a developmental change takes place during this cycle and it shifts one or two hours later in teenagers than in 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."
The study claims that a natural dip occurs in your sleep cycle from noon to 2pm. During that period, adolescents are more likely to fall asleep. The Chinese educational system is set up to allow children to nap, unlike the US or Ireland.
“Throughout childhood, U.S. kids experience decreases in napping tendencies. Kids are trained to remove their midday napping behaviour," said Ji. "Conversely in China, the school schedule allows children to maintain it."
The findings of the study suggests that there is an association between habitual midday napping and neurocognitive function, especially in China, where midday napping is integrated into society as a cultural practice.
Neurocognitive function is fundamental for learning, emotion and behaviour control.
Participants from schools in China had their midday napping, nighttime sleep duration and sleep quality, and performance on multiple neurocognitive tasks tested.
Ji also examined two dimensions of nap behaviour, frequency and duration.
The results found that routine nappers, who napped five to seven days in a week, had sustained attention, better nonverbal reasoning ability and spatial memory.
The study also revealed that participants who slept between 30 to 60 minutes produced better accuracy in attention tasks as well as faster speed.
Contrary to pre-existing literature, the researchers found a positive relationship between midday napping and nighttime sleep. To their surprises, those who nap more often tended to have a better nighttime sleep.
"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," the researcher 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," she adds.
So, how do you get the most from a nap? According to the research, the “sweet spot” is between 30 to 60 minutes, as a nap longer than an hour interferes with your natural sleep cycle. Ji also recommends not to nap after 4pm or over-napping.
