A quick sampling of metro area high schools shows start times ranging from 7:25 or 7:35 a.m. (at Lindbergh High School, Ladue Horton Watkins High School, and Parkway South High School) to 8:45 a.m. (at John Burroughs School on late-start days). The times fall along a bell curve, with most bells ringing around 8 a.m.
That’s way too early.
For centuries, parents have dragged teens out of bed to teach them discipline and responsibility. But it turns out that the teens weren’t lying abed in a luxury of lazy self-indulgence. Instead, they were responding to their bodies’ changing circadian rhythms.
After puberty, the natural sleep cycle shifts, so even if a teenager is exhausted at 10 p.m., he or she might not be able to fall asleep until after 11 p.m. Researchers have sampled saliva and found that what is called the dim-melatonin time—when the body begins secreting melatonin and eases toward sleep—occurs later at night than it did pre-puberty, and the melatonin secretion lasts later the next morning. Regardless of what time their owners arise, teens’ brains don’t start to wake up until 8 a.m.
We shift that natural cycle at our peril: A National Sleep Foundation survey found that 60 percent of teens complained of feeling tired during the day. The foundation says teens need more than nine hours of sleep but average less than seven.
There are consequences: Insufficient sleep can affect academics, social life, and athletic performance. It can make kids more irritable, depressed, and impulsive. It can impair decision-making and exacerbate substance abuse. It can cause health problems and increase all sorts of risks.
Three separate studies, all published in the Journal of Clinical Sleep Medicine, have found sharply higher crash rates for teenage drivers in Virginia counties with schools that have earlier start times. The data were from 2007 to 2011, and the school start times were roughly 7:20 a.m. and 8:45 a.m. In each study, the crash rate in the county with the earlier school start time was significantly higher—by as many as 20 crashes per thousand. A three-year study done at the University of Minnesota found that with later start times, teens’ attendance, health, mood, alertness, and behavior improved.
In August 2014, the American Academy of Pediatrics recommended that middle and high schools start at 8:30 a.m. or later. The policy statement’s lead author, Dr. Judith Owens, called adolescent sleep deprivation “one of the most common—and easily fixable—public health issues in the U.S. today.” The following month, U.S. Rep. Zoe Lofgren (D-California) introduced yet another version of her ZZZ’s to A’s Act, which would require the U.S. Secretary of Education to study the relationship between school start times and adolescent health, well-being, and performance. Lofgren has been trying to get school start times moved to 8:30 a.m. since 1998—but she can’t seem to rouse her colleagues.
