By Rima Himelstein, M.D.
It’s 11 a.m. on a Saturday morning … and, yes, I do know where my children are. They’re sleeping, just like we used to do when we were teenagers. But do they really need this extra sleep … or should I wake them up?
According to the National Sleep Foundation, teenagers need 9-1/4 hours of sleep per night—mainly because hormones needed for growth and sexual maturation are primarily released during sleep. But the average teenager only gets about 7 hours of sleep per night. And they feel it!
Why don’t teens just go to bed earlier? Everyone has an internal biological clock or circadian rhythm that influences his or her sleep patterns. Before puberty, the circadian rhythm directs most children to naturally fall asleep around 8 or 9 p.m. Puberty changes teens’ circadian rhythm, delaying the time they start to feel sleepy—often until 11 p.m. or later. That’s partly because melatonin, the brain chemical that makes us feel sleepy, is released later in teens than in other people.
What are the risks when teens don’t get enough sleep? According to sleep experts, teens may experience ...
- “Sleep debt.” When a teen’s tendency to fall asleep later is coupled with early school start times, most teenagers end the week with a sleep debt of 5 to 10 hours. And if they “binge sleep” on the weekends, it will be harder for them to fall asleep at a reasonable time on Sunday night. And so the vicious cycle perpetuates itself.
- Limited ability to learn, concentrate, and solve problems. Inadequate sleep affects school performance. Teens gather information during the day and their brains consolidate it during sleep, so they’re really not learning until they literally “sleep on it.”
- Falling asleep in school. According to the National Sleep Foundation’s 2006 Teens and Sleep poll, more than one quarter of high school students fall asleep in class.
- Moodiness … irritability … and even depression may result.
- Drowsy driving. Being sleep deprived has the same effects as a blood alcohol level of 0.08%—enough to qualify as DUI. Drowsy drivers, especially if they are under the age of 25, cause more than 100,000 crashes, 40,000 injuries, and 1,500 deaths in the U.S. every year.
- Sports injuries. New research has found that adolescent athletes who slept less than eight hours every night were more likely to suffer athletic injuries than those who slept more. Those who logged eight or more hours were 68 percent less likely to be injured.
How can parents help teens get more sleep? Here are a few small steps that can make a big difference:
- Establish a routine. Encourage your teen to stick to a regular sleep schedule—going to bed and getting up at the same times every day. On weekends, teens should not go to sleep more than an hour later or wake up more than 2 to 3 hours later than during the week or they’ll disrupt their internal clock.
- Adjust the lighting. As bedtime approaches, dim some lights and turn off others. In the morning, expose your teen to bright light. These simple cues send the body “sleep” and “wake” signals.
- Keep naps short and early. Sometimes a short nap after school can rejuvenate, but naps that are longer than 30 minutes or too close to bedtime will make it harder to fall asleep.
- Avoid caffeine—including caffeinated drinks, coffee, tea, and even chocolate—late in the day.
Here’s the challenge: teens’ natural sleep circadian rhythm doesn’t fit with school start times. Most teenagers need an alarm clock (often called “Mom”) to wake them on school days. Then, when they find themselves dressed and at school, they find it hard to be alert. Some research has shown that teens in schools that start later have better attendance, are more alert, and are less likely to be in a bad mood or feel depressed.
Something to sleep on: do you think middle and high schools should start later?
Rima Himelstein, M.D., is a Crozer-Keystone Health System pediatrician and adolescent medicine specialist.