(WKBW/ABC News) School bells shouldn't be competing with alarm clocks!
A study in the journal "Child Development" finds evidence that burning the midnight oil to cram for tests is time wasted.
Researchers asked 535 students from grades nine to twelve to keep a diary of how long they studied, how long they slept and whether they had academic problems the next day, such as not understanding something taught in class or doing poorly on a test or homework.
The research found that when study time cut down on sleep time, kids performed more poorly the next day in class.
Researchers say that doesn't mean teens should study less, but if they sacrifice sleep for study, it may hurt more than it helps.