High school students with heavy academic course loads often find the demands of homework colliding with the need for adequate sleep. And a new study published in the journal Child Development finds that when teens don't get the sleep they need on a given night, the next day all kinds of things can go poorly.

"What we learned is that when kids cram, particularly at the expense of sleep, the next day they're more likely to have academic problems even though they spent more time studying that night," explains researcher Andrew Fuligni of UCLA.

"These findings may come as a surprise to many researchers, educators, parents and teens who assume that more studying will surely lead to better grades," says Amy Wolfson, a professor of psychology at the College of the Holy Cross in Worcester, Mass.

The study builds on a body of evidence that finds sleep and learning are inextricably linked.

Source: NPR
http://www.npr.org/blogs/health/2012/08/21/159435167/high-school-daze-the-perils-of-sacrificing-sleep-for-late-night-studying