Getting up is especially difficult for teens, but when experts looked at the sleep patterns of nearly 3,000 students, they found that morning lethargy may be a biological problem.
For years, Caelin Jones says he couldn't function in the mornings. His alarm went off at 6am, but his mind struggled to wake up for hours.
"I would get to school and pretty much be the same as all the other kids," he said. "We were all just bleary-eyed and kind of, like, 'why are we here at this time? I don't want to be here!'"
That attitude is common and may not be entirely a teenager's fault. Sleep experts say teens simply can't fall asleep as early as others.
"It's not just that they don't want to or that they have a lot of activities or Facebook or homework time, which they do as well. But they physiologically can't fall asleep earlier anymore," said Dr. Lisa Meltzer with National Jewish Health.
Meltzer is a sleep psychologist who says the production of melatonin -- the hormone which relates sleep -- shifts by about two hours in teenagers. That means they would do better to sleep later in the mornings. Of course, schools don't allow it.
To see how that impacts teens, she compared typical students to homeschooled students and found that the teens who were homeschooled sleep 90 minutes more a night. In fact, they wake up nearly 20 minutes after other schools have started.
In public schools, nearly half of all students don't get enough sleep, she said.
"It impacts every aspect of functioning," Meltzer said. "So you think about academics, their ability to learn, concentrate, pay attention is all diminished when you haven't had enough sleep."
It also affects everything from a teenager's mood to their ability to drive. Meltzer says this study shows that schools should rethink their hours.
Experts say schools that have moved their start times back report less tardiness and higher graduation rates, and home schooled kids were even more rested.
Take ABC13 with you!
Download our free apps for iPhone, iPad, Android and Blackberry devices