School Days and Body Clocks

Daughter has been back in school for a full 3 weeks now, and we’re already feeling the effects of teen biorhythms vs. school schedules. Chances are, this phenomenon runs rampant in your school district, too — quite possibly in your own home.

Those brave enough to live with adolescents know that they tend to stay up into the small hours of the night and, if left to their own devices, sleep until noon. Your child, who once awoke at the crack of dawn eager to watch cartoons on Saturday morning, has now turned into a sleepy young adult who wouldn’t wake up if a bomb went off in the next room. What you may not know is that there’s a solid biological explanation for this.

Sometime in late puberty, the body secretes the sleep-related hormone melatonin at a different time than it normally does. This changes the circadian rhythms that guide a person’s sleep-wake cycle.

Mid-evening, let’s say 8 PM, when an adult is starting to wind down and feel sleepy, preparing to go to bed between 10 and midnight, the typical teen is wide awake. Their internal body clock has slowed, and they may not feel sleepy until 1 or 2 AM. Those late hours spent on homework, Facebook, and texting sessions are no accident. They’re the result of powerful biological signals.

At the same time, studies show that the changes taking place in teen bodies require more sleep, not less. Younger children need about 10 hours each night, while adolescents need nearly the same — 9 1/2 hours. They rarely get that much, and many end up chronically sleep deprived.

Most high school class schedules begin early, between 7:30 and 8 AM. If your 16-year-old finally falls asleep at midnight  (optimistic) and the alarm goes off at 6:30 for a 7:30 start time (ridiculously optimistic, particularly for girls), that’s 6 1/2 hours of sleep — a full 3 hours short of what they need. In a recent study 10% of teens reported sleeping less than 6 hours a night.

Contrast this with the body rhythms of your 9-year-old, who’s happy to go to bed around 9 PM, especially if they’ve already gotten their required dose of computer time or must-see TV. Start time for most grade schools is about 8:30, allowing for 10 1/2 hours of sleep — in line with what they need and some to spare.

Something is wrong with this picture, and I’m not the first to point it out. The Mayo Clinic believes that teen sleep deficit is a big deal and can have serious consequences, including behavior problems, school failure, and depression.

So what’s going on? Why do we prop up our sleepy high-schoolers at dawn when they can’t possible learn, while our younger ones are bright-eyed and wide awake so much earlier? Why don’t we flip start times and let the big guys get in a few extra zzzzs?

As with so many things, habit, bureaucracy, and scheduling are the culprits here. The high school day includes academic classes, extracurricular activities, and, most important in so many schools — varsity sports. To fit it all in before dark you have to start early. And then there are those all-important school bus schedules.

School districts, like other organizations, follow the path of least resistance, and the easiest way to make the schedule work is to get those teenaged butts in chairs early, even if they can’t keep their eyes open.

It won’t change until parents join together and demand it. I believe our schools are there to serve kids, not the other way around. We’re more involved in our children’s lives than ever (often TOO involved), so why aren’t we screaming and yelling about chronically exhausted kids struggling to make sense of AP calculus while their brains are still in REM phase? Stand up, mamas! Start now, and work on getting local schedules changed for your younger ones who will be high-schoolers down the road.

‘Til then, here are some suggestions to keep your teenager sleep-healthy:

  • Stick to a schedule, as hard as it is. Establish a reasonable sleep time and practice it. Turn off electronic stimulation (cell phones, computers, video games, TV) and create a dark, quiet environment that encourages sleep.
  • Bring back pre-sleep rituals. When they were tiny you had bedtime rituals — a bath, a story, a lullaby. Help your teen come up with current ones that work. Maybe a shower and light pleasure reading or calming music. Sleep meditation tapes may work.
  • No long naps. A quick 15-30 minute refresher after school may help to make it through homework, but a long snooze will only make things worse and interfere with a good night’s sleep.
  • Limit caffeine. And this goes for soda and energy drinks, as well as coffee. Stick with water and fruit juices during the evening.
  • Add physical activity to the mix if it’s not already there. Regular exercise works wonders for sleep.
  • Avoid over-scheduling. Most challenging and most important. If yours is on the varsity basketball team, in the school orchestra, and taking after-school dance, homework may not get started until 9 or later most nights, and that pushes bedtime beyond what’s reasonable. Keep school night extracurriculars spread out over the week and over the year to avoid crunch-time.

Easy to say, hard to do. Daughter has a ridiculous academic load (a typical junior year schedule at her school), is on the cross country team and in the school play. Add the student newspaper and teen social life and her plate is more than full. I’ll admit that she rarely achieves those 9 1/2 hours a night, but we’re shooting for it.

And I’m still nagging those school administrators to stretch the start time …

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Rachel Zahn, MD is a pediatrician turned health writer who had three kids during medical school and pediatric training—crazy, huh?

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2 responses to “School Days and Body Clocks”

  1. Brandon Boyd

    I laughed at your humorous metaphors and i greatly agree with what you have to say because i am one of those teens. i find it very difficult to get to bed and i do sleep in to about noon depending on what time i went to bed. its a hard schedule to keep up with especially at school. I find high school hour for us teens a great struggle.

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