A really interesting study from Child Development in Feb 2013 entitled To Study or to Sleep? The Academic Costs of Extra Studying at the Expense of Sleep looks specifically at high school students who trade sleep for extra studying time, and whether or not the net result is academic improvement (short answer: no, academics suffer). The abstract says:
“Results suggest that regardless of how much a student generally studies each day, 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. Because students are increasingly likely to sacrifice sleep time for studying in the latter years of high school, this negative dynamic becomes increasingly prevalent over time.”
“Our results suggest that, across the years of high school, the trade-off between daily study time and sleep becomes increasingly associated with academic problems. In the latter years of high school, days of extra studying tend to be followed by days with more academic problems. In 9th grade, days of extra studying have no association with the following day’s understanding of class material or test performance; in 10th grade, however, adolescents report more such academic problems on days after they spend more time studying than usual, and this troublesome association becomes even stronger in 12th grade. The association between study time and academic problems occurs regardless of whether or not students have a test coming up and, therefore, is not simply an artifact of studying for and taking a difficult test.
Although we expected that nights of extra studying might not be as effective as students suppose (Pilcher & Walters, 1997), it was somewhat surprising that nights of extra studying would be associated with worse academic functioning the following day. This surprising finding, however, made more sense once we examined extra studying in the context of adolescents’ sleep. As other studies have found, our results indicate that extra time spent studying cuts into adolescents’ sleep on a daily basis (Adam et al., 2007). This trade-off between studying and sleeping occurs in 9th grade and becomes more dramatic in the latter years of high school. Our mediation results suggest that the reduced sleep that tends to occur on nights of extra studying is what accounts for the increase in academic problems that occurs the next day.”
“Sacrificing sleep for more studying time is a common, yet counterproductive strategy for adolescents, especially in the latter years of high school. 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. Our results suggest that the best studying strategy for adolescents who must juggle the demands of high school is to study consistently on school days. However, as adolescents progress through high school, their time becomes an increasingly precious commodity. On the basis of the mediation results, we speculate that if adolescents do need to study more than normal, they should not sacrifice sleep, but rather some other time-consuming activity. Parents and educators concerned about adolescents’ academic problems should emphasize the importance of sleep and maintaining a regular studying schedule.”
The study can be found at the Wiley Online Library (you must pay for access) but you can read a writeup of this study at 3 Tips for Parents to Teach Healthy Study Habits to Teens