It's been a couple of months since school started up, but for many teens the routine of getting up early never comes easy.
Elizabeth Cohen takes a look at a new study showing the benefits of delaying school start times in today's Health Minute.
It's 5:22 in the morning, and 16-year-old René Carrasquilla from Atlanta, Georgia is already getting up for school.
His bus comes at 6:20. The first bell rings at 7:25.
Doctors say teens need nine hours of sleep.
René doesn't get nearly that much.
9 hours of sleep? I don't think that's possible for high school if you have to get up at 5 or at 6. That means you have to be in bed at 8 or 9.
Experts say about 80 percent of high school students are sleep deprived. They're biologically programmed to stay up late.
"There clearly is a shift in adolescents to a natural bedtime and wake time being 2 or even 3 hours later than it was in elementary school."
Teen sleep expert Judith Owens wants high schools to consider starting later.
She did a study at St. George's School in Rhode Island where they delayed school start time by thirty minutes.
The results were stunning: Kids were much more alert.
"Starting school later actually got kids to bed earlier, and we think that was in large part by virtue of their being better rested, they were able to be more efficient and get their work done."
Getting just a few more precious minutes of sleep would certainly make a difference to rené and his family.
For today's Health Minute, I'm Elizabeth Cohen.