(RxWiki News) The big test is tomorrow. Time for an all-nighter of cramming so you can be sure to ace it right? Wrong.
A recent study has found that even one night without enough sleep can cause you to do more poorly on the test than if you had gotten the sleep you really need.
"Get 7-9 hours of sleep every night - especially before big tests."
The long-term study, led by Cari Gillen-O'Neel, a PhD student in development psychology at the University of California at Los Angeles, looked at how teens' study and sleep time habits were linked to their school performance the next day.
The researchers tracked 535 Los Angeles 9th-graders over four years. The teens filled out daily diaries of their sleep and study time for two weeks during their 9th grade, 10th grade and 12th grade years.
The diaries also asked about whether they had either of two problems in school: not understanding something taught in class or doing poorly on a test, quiz or homework.
They found that less sleep was linked to both problems. Teens who stayed up to study instead of getting enough sleep had trouble understanding material the next day and tended to do more poorly on tests and quizzes.
"Sacrificing sleep for extra study time is counterproductive," said senior author Andrew J. Fuligni, a professor of psychiatry and biobehavioral sciences at the Jane and Terry Semel Institute of Neuroscience and Human Behavior at the University of California at Los Angeles.
"If that student sacrifices sleep time to study more than usual, he or she will have more trouble understanding material taught in class and be more likely to struggle on an assignment or test the following day," he and the other authors wrote.
William Kohler, MD, director of the Florida Sleep Institute in Spring Hill, Florida, echoed the authors of the study in calling it counter-productive to trade sleep time for study time.
"An adequate quality and quantity of sleep is needed for us to function at our maximum," he said. "This study further emphasizes the need for that sleep."
The authors noted that students' strategy of losing sleep in exchange for studying more becomes more common as students get older.
"Adolescents devote less time to sleep as they age, and when they sacrifice the precious little sleep they have for extra studying, it has negative consequences for their daily academic performance," they wrote. "The best studying strategy for adolescents who must juggle the demands of high school is to study consistently on school days."
The authors recognized that students may need to study a great deal, and they do not recommend cutting down on study time as a big test approaches. But they recommend cutting out another activity rather than sleep.
"Parents and educators concerned about adolescents’ academic problems should emphasize the importance of sleep and maintaining a regular studying schedule," they wrote.
Dr. Kohler noted that this study had some faults because it was based on self-reported questionnaires from the students, but its strength was having a large group of students.
The study was published August 20 in the journal Child Development. The study was funded by the Russell Sage Foundation. The authors did not note any information regarding possible conflicts of interest.