DAVID GREENE, HOST:
It is back-to-school season, and as parents of teenagers know, high school is when the need for sleep crashes up against the need to do homework. As NPR's Allison Aubrey reports, a new study finds sacrificing sleep might not pay off.
ALLISON AUBREY, BYLINE: The best part about senior year of high school - according to rising 12th graders David LoBosco and Patrick Ottolini - is that junior year is now behind them, as is some of the pressure.
DAVID LOBOSCO: Last year, I took a lot of, like, hard classes.
AUBREY: There were AP-college level course, the SAT to prep for. Eleventh grade is tough - a make-it-or-break-it year for college applications. So, what did all this mean for David's schedule?
LOBOSCO: I would start homework right when I got home and I'd be up until, like, one, 1:30 doing homework. So...
AUBREY: And how do you feel the next day when you stay up to 1:30?
LOBOSCO: I'd feel really tired and groggy and unmotivated and not wanting to do it all over again, I guess.
AUBREY: Especially when the day begins at 6:30 in the morning. David's friend, Patrick, who had a similar schedule last fall, says it's hard to stay awake.
PATRICK OTTOLINI: Especially through, like, the middle of the day and everything. It just, like, catches up. It's not good.
AUBREY: And a new study of high school students published in the journal Child Development finds this experience is typical. When students don't get the sleep they need on a given night, the next day, all kinds of things can go poorly. Professor Andrew Fuligni of UCLA led the study.
ANDREW FULIGNI: What we wanted to do is to get a very detailed picture of what the daily life of teenagers is like and how they manage different demands in their life.
AUBREY: To do this, he and his colleagues asked high schoolers to complete a nightly checklist with a series of questions about their activities, such as...
FULIGNI: Did it eat a meal with my parents? Did I study that night? How much did I sleep the prior night?
AUBREY: They also answered questions about how they felt and how they performed at school.
FULIGNI: Did you have trouble or difficulty on a test that day? And did you have difficulty understanding things that were being taught in class?
AUBREY: And Fuligni says what he found is that on nights when students reported fewer hours of sleep, they reported problems at school, too.
FULIGNI: What we learned is that when kids cram - particularly when they cram at the expense of sleep - the next day, they are more likely to have academic problems, even though they sort of spent more time studying that night.
AUBREY: The results do not surprise sleep expert Helene Emsellem. She directs the Center for Sleep and Wake Disorders in Chevy Chase, Maryland, and treats lots of teenagers. She says what people don't realize is that learning and sleep are inextricably connected.
HELENE EMSELLEM: Several things happen during sleep. We don't just physically restore ourselves.
AUBREY: We also process all the information we've collected in a day.
EMSELLEM: We take the information and we organize it, and we make all the connections.
AUBREY: So when a student sits down the next day for a quiz...
EMSELLEM: If a question isn't worded exactly the way the information was presented in class, you have drawn enough connections during the night to pull that information out and answer that question correctly.
AUBREY: Maybe this explains why student Patrick Ottolini has realized that it's not always the best strategy to stay up late and cram.
OTTOLINI: If it's like a big test, no, it's not going to work at all.
AUBREY: Instead of cramming, he's learned from experience it's best to pace yourself and find smaller chunks of time each day to study. His friend David says if you need to, the night before a quiz, it's better to get some sleep and set the alarm.
LOBOSCO: You know, you wake up early in the morning, and you study for that.
AUBREY: Helene Emsellem says the most helpful advice she gives families...
EMSELLEM: Having a lights-out time in the house where everyone goes to sleep.
AUBREY: Which says is ideal for teenagers and good for their parents, too. Allison Aubrey, NPR News.