As a mother of three teenagers, observing their current sleep habits makes me stop and wonder—why do all three of them appear to have morphed into nocturnal creatures who sleep-in until lunchtime when given the opportunity on weekends? After a bit of research on the biological changes that are happening to my adolescents, the answer becomes clearer.
A teen’s internal clock
Simply put, our bodies have an internal clock called the “circadian.” It comes from the Latin word meaning “about 24 hours.” Our circadian clock influences things like body temperature, hormonal changes, sleep cycles and even our appetite. Our body’s processes (biological and physiological) that follow this clock are known as our circadian rhythms.
Before our kids reach adolescence, these circadian rhythms typically lead most children to naturally fall asleep around 8 or 9 p.m. However, puberty changes a teen's internal clock. It can delay the time he or she starts feeling sleepy—often until 11 p.m. (or in our house, even later).
This natural shift in my teens' circadian rhythm causes them to instinctively feel alert later at night, making it difficult for them to fall asleep before 11:00 p.m. In teenagers, research shows that melatonin levels in the blood naturally rise later at night than in most children and adults. This helps me understand why I am feeling relaxed and ready for sleep and they come alive at 10 p.m.
On average, teens optimally need 9¼ hours of sleep a night, with a minimum of 8½ hours. As I can attest during our typical school week, my teens don’t get this much sleep. In fact, according to the National Sleep Foundation more than 25 percent of teens report sleeping only 6½ hours a night or less. This lack of sleep can influence their circadian rhythm and therefore throw them out of balance. Speaking through the eyes of a mother, teens already have a surplus of physical and emotional stress in their lives. They don’t need anything else to contribute to knocking them out of equilibrium.