Originally posted on Craig Canapari, MD:
A few years ago, I had a sixteen year old come into sleep clinic for insomnia. He was a hard-working student in a good school district. I asked him to describe his sleep problems to me. “I finish my homework at midnight every night,” he said, “and I can’t fall asleep by 12:10 AM.” Each of his Advanced Placement classes had 1-2 hours of assigned homework per night and he was not routinely finishing homework until 11 PM or 12 AM. This may be an exaggerated case [and note that the details have been changed a bit to protect patient privacy.] However, let’s do the math. The typical school day for a high school student in this country is between 6.5-7 hours per day. Most school districts start between 7-8 AM for high school students. Thus, kids are getting out of school between 2-3 PM. Many students do extracurriculars for a few hours after school and cannot start homework until after dinner (say 6:30 PM). The maximum recommended homework for a high school senior is three hours per night; for younger children, it is ten minutes per grade. If the student goes to sleep at 10 PM and gets up at 6 AM ( a typical wake time around here for high school students), this allows 8 hours of sleep. However, the typical teenager requires between 8.5-9 hours of sleep per night, so even a teen with good sleep habits generally sleep deprived. In Boston, this problem is frequently exaggerated by school choice where some children are assigned to better schools which are a long bus ride away. (These issues exist elsewhere. My friend Trapper Markelz grew up in Alaska and regularly took 45 minute bus trips twice a day to school.)
In their recent article, “To Study or to Sleep? The Academic Costs of Extra Studying at the Expense of Sleep“, Cari Gillen-O’Neel and colleagues studied the effects of staying up late on students. They studied 535 kids through high school. The average sleep time for these teens diminished from 7.6 to 6.9 hours of sleep from 9th to 12th grade. When they examined what happened when teens stayed up late to study for finish a project, they found that
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.