Should Kids Start School Later? Study Says Start Times Tied to Health

Blog School Sleep Web

A recent study says starting school later could have a positive impact on kids’ health.

Most parents are familiar with the agony of getting kids up early enough to make it to school on time. But some might be unaware that a lot of that difficulty stems from biology. Teens’ circadian rhythms, or natural body clocks, for instance, clash with the start times of most of their schools, meaning it’s likely more difficult for them to rise before 8 a.m. A recent Canadian study published in the Journal of Sleep Research is one in a growing body of research suggesting a solution: Starting school later, they say, could have a positive impact on kids’ health. 

After evaluating data from 30,000 Canadian students who responded to surveys conducted in collaboration with the World Health Organization, researchers at McGill University concluded that teens that started school earlier didn’t get the recommended amount of sleep and were more likely to feel tired in the morning. 

It’s possible that even fewer teens in the United States get a healthy amount of sleep: Less than one-third of them get the 8.5 to 9.5 hours of sleep a night recommended by the American Academy of Pediatrics. 

It’s a common problem among high-school-age patients, shares Dr. Sarah Morsbach Honaker, director of behavioral sleep medicine at Indiana University Health. “But the phenomenon is more linked to puberty than to age,” Dr. Honaker says, explaining that during puberty, teens’ sleep clocks become delayed so they feel tired later and later at night and it’s more natural to sleep later in the morning. The study researchers estimate that delay is around two to three hours.

“There might also be a genetic component,” Dr. Honaker says. “Some teens who have a lot of night owls in the family are more likely to have delayed sleep systems.”

The cycle of poor sleep is a growing health concern, experts say. A report by the Centers for Disease Control and Prevention noted that adolescents who don’t get enough sleep are more likely to be overweight, to not exercise daily, and are more likely to suffer depressive symptoms. Some research suggests that lack of sleep is tied to increased substance abuse risk and poorer school performance.  

“Not getting enough sleep can affect learning, certainly,” Dr. Honaker says. “There are a number of studies showing that even missing 20 to 30 minutes of sleep on a chronic basis can cause neurocognitive deficits and a reduction in reaction time. We also know that people suffering from sleep deprivation might not be able to judge how impaired they are after not getting enough sleep; people tend to underestimate how much it’s affecting them.”

One reason American teens tend to sleep even less on average than Canadian kids do is that U.S. school start times are earlier. Canadian schools typically start at 8:43 a.m., whereas schools in the United States began at 8:03 a.m. on average during the 2011-2012 school year, according to the CDC. Those start times can have a big impact, this study suggests. 

Even a 10-minute delay in start time corresponded with three additional minutes of sleep and a two percent lower probability that students felt tired the next day, the authors found. Their recommendation for school days to start later in the morning echoes that of the American Academy of Pediatrics, which suggests that school start no earlier than 8:30 a.m. 

U.S. schools seem to be coming around to the idea of pushing back school start times, but because there’s often pushback, change has been slow. Grade school kids starting school way before parents need to be at work can create childcare issues for some families. And many districts need to stagger busing times between grammar, middle, and high schools, which might mean that younger kids are waiting for their buses before sunrise when it’s less safe. 

The CDC notes that greater education about the health effects of sleep deprivation on kids – including how better sleep could improve test scores, as some research suggests – as well as how worry about the effects of later start times might be unfounded could help sway school districts in the United States to better align start times with health advocates’ recommendations. In the meantime, Dr. Honaker recommends that teens try not to nap after school, which makes it harder for them to sleep at night, and to keep a regular sleep/wake schedule on the weekends rather than sleeping in. 

-- By Virginia Pelley

Viewing all posts in …