A number of my friends and acquaintances have commented to me that their teenaged children have a lot of trouble waking up in the morning. The usual explanation is that teens' sleep cycles are shifted, going to bed later and waking up later. Some experts in sleep medicine have even recommended that schools start much later in the morning to accommodate for this phenomenon in teenagers.
Besides shifted sleep cycles, here's another interesting perspective on why teens are so sleepy in the morning:
I've described in previous blogs and in my book, Sleep, Interrupted, the concept of laryngeal descent. Your voice box (larynx) had to drop down below the tongue to allow for complex speech and language. Comparative anatomists and evolutionary biologists have stated that speech and language development was ultimately detrimental to humans. This is why only humans have various breathing and swallowing problems that other animals, for the most part, don't suffer from.
In humans, the voice box continues to descend throughout life, but there are two major stages of laryngeal descent that are important. The first one occurs around 4-6 months, when the voice box drops down from behind the tongue (at vertebral levels C3-C4) to a position below the tongue. This process also create a space called the oropharynx between the soft palate and voice box, where the tongue can fall back more easily. Before this happens, human infants can suckle and breathe at the same time, but during this transition they have to relearn how to swallow and breathe. Interestingly, this is also the time when the rate of SIDS (sudden infant death syndrome) is at its' highest.
The second stage occurs during adolescence. The voice box begins to drop even further, reaching its' final relative position in the late teens (vertebral level C7). In fact, the voice box continues to drop another 1/2 vertebral height well into your 80s (see figure 2.1 in this link). In boys, this happens to a greater degree than in girls, leading to a deeper voice in men. As the voice box drops lower and lower, the more your tongue is susceptible to collapse while sleeping supine (on your backs), and when in deep sleep, since your muscles are most relaxed during this time. If you add to this additional dental crowding and jaw narrowing, you'll see that it can explain many of the health problems that all modern humans suffer from.
This leads to less efficient sleep, leading the teen to be attracted to stimulating activities that compensate for this fact. No wonder many teens are so incredibly productive, engaging in sports, clubs, academics, and social activities. Because of this mental, emotional and physical overload, they can't shut down their minds at night, leading to delayed sleep times. But then they are forced to wake up long before they achieve the necessary hours of restorative sleep.
Add to this all the distractions of modern society, including cell phones, texting, chats, light bulbs, computers and TV. Also notice how bright the LED lights are in all the bedroom electronic devices. One modern LED is now 10 times brighter than a traditional night light.
Do your teenaged children have trouble getting up in the morning? What kind of activities are they engaged in during the day? What's their nighttime routine before going to bed? Please enter your response to this blog in the comments box below.