Every morning for the past couple of months, getting my teenage daughter out of bed before about 10 a.m. requires me to say something like: “If you don’t get up soon you’re going to miss seeing Taylor Lautner (or insert some other teenage heartthrob) on TV.” That at least gets her stirring.

Well, now that school is back in session, those late-morning-sleep-in sessions just don’t work. So, what can be done to get your teenager fired up in the mornings? For the answer, we have to explore why teens might not be able to fall asleep before midnight.

The funny thing is that some schools seem to have it a little off when it comes to teenagers. They begin school as early as 7 a.m.. Fortunately for my daughter her school district starts at a better-suited time for teens (after 8 a.m.). Most teens need about nine hours of sleep but few get that once school begins. Homework and extra-curricular activities take up a good portion of the day and push bedtimes back reducing the amount of sleep teens get. But even without the school workload teens would still prefer to stay up late—it’s how they’re designed.

In 1996, a survey of 7,000 students in Minnesota showed that students who started class after 8 a.m. performed better than students who started earlier. Brown University Professor Mary Carskadon agrees with this. She led a team of researchers who helped prove just how out of it teens really are in the early morning hours.

By checking teenagers’ saliva measured at different times of the day, the researchers discovered that the melatonin levels rise later at night for older kids and remain at a higher level in the morning. Melatonin is a hormone produced by the pineal gland that helps set our biological clock; it lets our bodies know that it’s time to sleep. Teens also seem to be less sensitive to daylight which helps stop the production of melatonin. This is why young children can often fall asleep easier and earlier in the evening when the sun goes down and then wake as it rises.

One idea for dealing with sleepy teens, that remains ineffective, is to simply send them to bed earlier. Carskadon says that just doesn’t work. She says this is because of forbidden zones which are the times that are extremely difficult for teens to fall asleep such as the evening hours up to about 11 p.m.. According to Carskadon, part of the problem is the delayed rise in melatonin (as mentioned earlier) and the fact that teens are easily stimulated by various activities.

So now let’s go back to the question about what can be done to help your teen get the rest needed to wake up refreshed. Carskadon suggests limiting exposure to light in the evening hours. In fact, this is good advice for anyone who is having difficulty sleeping at night. She also suggests teens maximize their daylight exposure first thing in the morning. This helps to reset their biological clock to an earlier wake/sleep cycle. Your teen might find it helpful to use a blue light treatment.  I have found it very effective (especially when the heavy fog covers the bright sunshine as it has so many mornings). The light treatment is manufactured daylight and helps to wake and reset your biological clock. Readjusting your biological clock requires a repetitive pattern. So, sleeping really late on the weekends and rising early during the week will make it difficult for the body to learn and set a wake/sleep cycle. The other important thing to remember is that it takes time to adjust—so be patient!