Every school year, parents and guardians once again face the old struggle of cuddling children who are limp out of bed in the morning. It can be especially difficult for a parent with a child in her early teens or her teens.
Teenage laziness is sometimes blamed. But the main reason healthy people can’t wake up naturally without an alarm is that they aren’t getting the sleep their brains and bodies need.
This is because research shows that adolescents need at least nine hours of sleep a day to be physically and mentally healthy.
However, it is highly unlikely that you know a teenager who gets enough sleep. According to the Centers for Disease Control and Prevention, less than 30% of her high school students (or grades 9 through her 12) in the United States adhere to recommended sleep times. Nearly 60% of her middle school students in grades 6-8 don’t get enough sleep at night.
But my lab research shows that teens have a much higher percentage and sleep too little.
I am a professor of biology and have studied sleep and circadian rhythms for over 30 years. For the past seven years, my lab at the University of Washington has been conducting sleep studies of her teenagers in the Seattle area. Our research shows that, like the rest of the United States, high school students in Seattle aren’t getting the amount of sleep they need. In our study, when we objectively measured the sleep of 182 high school sophomores and her junior year, she was the only two who slept at least her nine hours a night during her school days.
Our study and that of other researchers show that there are three key factors behind this sleep deprivation epidemic. Sun exposure and excessive exposure to bright lights and screens late at night.
teenage sleep biology
When you go to bed, when you fall asleep, and when you wake up are governed by two main factors in your brain. The first is the so-called “Arousal Tracker”. This is a physiological timer that increases the need for sleep the longer you are awake. This is partly a result of the accumulation of chemical signals emitted by neurons, such as adenosine.
Adenosine builds up in the brain when we are awake, making us more sleepy as the day goes on. It builds up throughout the day, usually late at night, until it reaches a sufficient level.
The second factor that drives your sleep-wake cycle is your 24-hour body clock, which tells your brain what time of the day to wake up and what time to go to bed. This biological clock is located in an area of the brain called the hypothalamus. The clock is made up of neurons that coordinate brain regions that regulate sleep and wakefulness to her 24-hour sleep/wake cycle.
These two regulators operate relatively independently from each other. However, under typical circumstances they are regulated so that people with access to electricity go to sleep late at night (around 10-11pm) and wake up early in the morning around 6-7am. increase.
So why do teenagers often want to go to bed later and wake up later than their parents?
During puberty, wakefulness trackers and body clocks have been found to conspire to delay the timing of sleep. First, adolescents may stay up late before their wake trackers feel sleepy enough to make them fall asleep.
Second, teenagers’ biological clocks are lagging, sometimes appearing to run at a slower pace and reacting differently to the light cues that reset the clock each day. This combination leads to a sleep cycle several hours later than older people. If an older person feels the signal to go to sleep around 11:00 pm from 10:00 pm, this doesn’t happen until after midnight in her teenage years.
How School Start Time Contributes
To help teens get more sleep, some school districts across the country are taking steps to delay middle and high school start times. The American Academy of Pediatrics recommends that school for this age group not start before 8:30 am. However, most high schools in the United States start at 8:00 a.m. or earlier.
Based on recommendations from sleep experts, the Seattle School District has delayed middle and high school start times by nearly an hour from 7:50 a.m. to 8:45 a.m. beginning in the 2016-2017 school year. A team that implemented the plan after the district enacted it found that students got 34 minutes of sleep each day. Additionally, the student’s attendance and punctuality improved, and her median grade increased by 4.5%.
Despite a wealth of research evidence and advice from virtually every sleep expert in the country, most school districts are still plagued by school start times that contribute to chronic sleep deprivation among teens. The start of is exacerbated by daylight saving time (when clocks are set one hour earlier in the spring). This time shift could become permanent in the United States in 2023, exposing teens to artificially dark mornings and exacerbating naturally delayed sleep timings.
Teach Teens Healthy Sleep Habits
School start times aside, children also need to learn the importance of healthy habits that promote adequate sleep.
Exposure to bright sunlight, especially in the morning, speeds up your body clock. This promotes an earlier bedtime and a natural early morning wake-up time.
By contrast, evening light (including light emitted from screens) is highly stimulating to the brain. Inhibits the production of natural signals such as melatonin. Melatonin is a hormone produced by the pineal gland in the brain in response to darkness at dawn. But when these cues are disrupted by artificial light in the evening, our body clock is delayed, causing us to go to bed later and wake up later in the morning. Thus, the cycle of having to wake a sleepy, yawning teenager out of bed to go to school begins again.
However, few schools teach the importance of proper routines and sleep timing, and neither parents nor teens are fully aware of their importance. It disrupts all physiological processes and is consistently associated with ailments such as depression, anxiety, obesity, and addictive behaviors.
Conversely, adequate sleep has been shown to be fundamental to optimal physical and mental performance, as well as helping reduce physical ailments and improving mental health.
This article originally appeared in The Conversation and has been independently reviewed to meet journalism standards.