It all happens because during puberty, our intrinsic body clock shifts later. Our body clock sets the rhythms in many of our systems, from when our melatonin and cortisol peak, to when we are most mentally sharp and physically coordinated. New research has shown that this swing to later timing is actually one of the first things that happen in puberty, even before physical changes can be observed.
Impact of teens sleep
The difficulty comes when teens (and tweens) need to be on an earlier schedule than their body is programmed for. When school starts early, students are in class, trying to pay attention and learn while their body and mind are asleep. Challenging, eh? Teens’ sleep basically gets squeezed between their later body clocks, and their early schedules. When high school start times were moved on hour later in Minnesota, there was an increase in amount of nightly sleep and subsequent improvement in school success: with improved attendance and most importantly increased graduation rates.
Other studies have looked at the amount of sleep teens get and many health parameters. Teens who get less sleep are:
Less motivated to exercise, contributing to the epidemic in childhood obesity
Get lower grades
Are more depressed
Many other negative effects
How to improve student sleep
The basic principle is to sleep and wake in accordance with the intrinsic body clock. So first of all, honor that teens are on a later schedule, and then set routines that help them be on as early as possible.
Avoid scheduling early morning activities when possible. Advocate for your children when parents and coaches are scheduling events.
Set a sleep / wake schedule, and stick with it.
Get bright light, preferably outdoor light, soon after waking each morning. This is most important in setting the body clock.
Sometimes these measures won’t have a big enough impact. There are medical interventions that can help teens sleep and wake on their early school schedule.