What Do Students Need Most? More Sleep

Jessica Lahey

When I travel around to schools to speak to students, I deliver one line in my talk that kills, each and every time. The students do not simply laugh, they whoop and holler, throw their heads back in open-mouthed guffaws and shake their heads in disbelief. I would love to lay claim to the funniest educator joke of all time, but sadly, I don’t have that kind of comic game. I’m not even aiming for their funny bone when I proclaim, “In order to function at your mental and physical best, adolescents should be getting at least nine hours of sleep a night.”

For many students, nine hours of sleep is so far beyond their reality that their only logical response is laughter. Four out of five adolescents are getting less than that, and more than half of them know they are getting less sleep than they need to function well.

Surveys conducted by the National Sleep Foundation reveal that teenagers are getting nowhere near nine hours of sleep a night. The average weeknight sleep duration for 13-year-olds hovers around 7 hours 42 minutes and decreases to 7 hours 4 minutes in 19-year-olds. And if you think your teenagers are getting enough sleep, think again. Ninety percent of parents say they believe their children are getting sufficient sleep, and yet when asked, 60 percent of teenagers report extreme daytime sleepiness.

Adolescents naturally get tired and fall asleep sleep later than younger children because adolescent sleep patterns adhere to what is called a “phase delay.” Delayed melatonin release in adolescent brains means they get sleepy later and subsequently wake later as well. When Edina, Minn., shifted its high school start time from 7:25 a.m. to 8:30, the district reported that students were getting more sleep with fewer sleep disturbances, they reported fewer episodes of depressive feelings, and on the whole received better grades. Most shockingly, the SAT scores of Edina’s top students rose from a pre-time shift average of 683 math/605 verbal to 739 math/761 verbal one year later.

Researchers have long understood that sleep is an important human activity (why else would we render ourselves helpless against predators for so many hours of our lives?), but they did not understand why. However, as Maria Konnikova described in the Sunday Review, one researcher may have figured out why sleep is one of the most important activities we can do to keep our brains healthy.

“Sleep, as it turns out, may play a crucial role in our brain’s physiological maintenance,” Ms. Konnikova wrote. “As your body sleeps, your brain is quite actively playing the part of mental janitor: It’s clearing out all the junk that has accumulated as a result of your daily thinking.” In other words, just as our kidneys remove accumulated waste products from our blood, sleep allows the brain’s own filtering system to sweep out the waste products that have built up over a day of cognitive exertions.

Sleep is a big deal for us all, but especially for children and teenagers, who spend even more time in the sleep cycles that are responsible for strengthening neural connections, consolidating memory and creating links between disparate memories.

Not convinced? Consider this (from the National Sleep Foundation’s report): less sleep means more traffic accidents, increased moodiness and aggression and, possibly, A.D.D. and A.D.H.D. diagnoses. It increases the risk of drug use and sports injuries. On the decrease? Academic performance: Po Bronson and Ashley Merryman’s book “Nurture Shock” sums it up best by linking the loss of one hour of sleep to the loss of two years of brain power.

I’m convinced that sleep is the single most important factor in ensuring my children’s health and academic success. Given the choice between one more review session for that French test and a bedtime that will ensure those nine hours, I will always encourage them to choose sleep.

How can you improve sleep habits at your house?

1. Make sleep a priority. It is not an afterthought or an optional activity that can be sacrificed. It is a vital biological function, not a waste of time.

2. Dim it down. Light delays sleep. Laptops, smartphones and tablets emit approximately 30 to 50 lux, about half the illumination of a room light, more than enough light to affect circadian rhythms and delay the production and release of melatonin. Keep hand-held digital devices, televisions and computers out of the bedroom.

3. No caffeine after noon. According to the American Academy of Sleep Medicine, while the effects of caffeine peak within 30 to 60 minutes, effects can last from 8 to 14 hours, which not only reduces total sleep time but can also reduce the duration of deep sleep cycles.

4. Encourage exercise. As reported in one study, subjects who exercised for three or four 30-minute sessions a week “slept, on average, 45 minutes to an hour longer on most nights, waking up less often and reporting more vigor and less sleepiness.”

5. Don’t go to bed angry. Life with an adolescent can be unpredictable, but try to avoid arguing or discussing upsetting issues in the evening. Even if you are really worked up over something that happened earlier in the day, if you can let it go until morning, do. You – and your teenager – will sleep more soundly for it.