Research Suggests that Later Start Times Help High School Students

Studies increasingly show that later start times for schools mean more sleep, lower accident rates, and higher academic achievement for middle and high school students.

Last week, the Davis school board, led by President Alan Fernandes, took action to move the district in the direction of implementing a policy that would adjust the start times for middle and high schools in the district to 8:30 a.m. beginning the next school year.

Mr. Fernandes told the Vanguard, “The Board voted 5-0 to request an implementation plan for a later start for our secondary students, as we believe the positive benefits of adequate sleep align with, and are central to, our mission  which focuses on the well-being of our students and goals of creating optimal conditions for learning.”

In his motion, he stated, “’School Start Times for Adolescents’ is a policy statement published in the September 2014 issue of Pediatrics.” According to this article, Mr. Fernandes continued, “the research clearly demonstrates that sleep deprivation is linked to increased rates of obesity and depression among youth. The article goes on to argue that a school start time of 8:30am or later is an easy fix that will mitigate problems caused by sleep deprivation among American adolescents and is an important step schools can do to improve the health and well-being of children.”

The motion specifically instructed “the Superintendent to appoint a committee formed for the purposes of recommending an implementation plan that would adjust the start times for all DJUSD middle and high schools to at or about 8:30am beginning at the next school year.”

It also requested the Superintendent direct the committee to “conclude the development of this implementation plan within 60 days so that the plan could be reported back to the Board in 60 days or at the next regularly scheduled board meeting immediately thereafter.”

While the Vanguard last weekend questioned whether adjusting the start time alone would be sufficient, the research seems to suggest that, in fact, adjusting start time alone would make a huge difference.

Board Vice President Madhavi Sunder told the Vanguard, “There are, of course, many causes for teens’ not getting the sleep they need — including electronics in the bedroom. But the nation’s leading children’s health and mental health professionals also lay the blame directly at the school house door.”

An August 2014 release from the American Academy of Pediatrics (AAP), which “recommends middle and high schools delay the start of class to 8:30 a.m. or later. Doing so will align school schedules to the biological sleep rhythms of adolescents, whose sleep-wake cycles begin to shift up to two hours later at the start of puberty.”

Ms. Sunder noted, “The American Academy of Pediatrics says ‘a too early start to the school day is a critical contributor to chronic sleep deprivation among American adolescents.’”

“The scientific evidence is clear: the time the first bell rings in the morning is a critical contributor to teens’ sleep deprivation. Schools are a crucial part of the problem, but we can also be a critical part of the solution,” she continued.

“Changing our bell schedule is a critical step. And we can do more,” she stated.

“Chronic sleep loss in children and adolescents is one of the most common – and easily fixable – public health issues in the U.S. today,” said pediatrician Judith Owens, MD, FAAP, lead author of the policy statement, “School Start Times for Adolescents,” published in the September 2014 issue of Pediatrics.

“The research is clear that adolescents who get enough sleep have a reduced risk of being overweight or suffering depression, are less likely to be involved in automobile accidents, and have better grades, higher standardized test scores and an overall better quality of life,” Dr. Owens said. “Studies have shown that delaying early school start times is one key factor that can help adolescents get the sleep they need to grow and learn.”

Sleep deprivation, according to these studies, has reached epidemic proportion, as a “National Sleep Foundation poll found 59 percent of 6th through 8th graders and 87 percent of high school students in the U.S. were getting less than the recommended 8.5 to 9.5 hours of sleep on school nights.”

The report cites a number of reasons for teens’ lack of sleep, including “homework, extracurricular activities, after-school jobs and use of technology that can keep them up late on week nights.”

While these are important factors and the AAP recommends pediatricians work with parents and teens about healthy sleep habits, they primarily argue that “the evidence strongly suggests that a too-early start to the school day is a critical contributor to chronic sleep deprivation among American adolescents.”

The report estimates that 40 percent of high schools in the U.S. currently have a start time before 8 a.m.; only 15 percent start at 8:30 a.m. or later. The median middle school start time is 8 a.m., and more than 20 percent of middle schools start at 7:45 a.m. or earlier.

“Napping, extending sleep on weekends, and caffeine consumption can temporarily counteract sleepiness, but they do not restore optimal alertness and are not a substitute for regular, sufficient sleep,” according to the AAP.

“The AAP urges middle and high schools to aim for start times that allow students to receive 8.5 to 9.5 hours of sleep a night. In most cases, this will mean a school start time of 8:30 a.m. or later, though schools should also consider average commuting times and other local factors,” the report continues.

“The AAP is making a definitive and powerful statement about the importance of sleep to the health, safety, performance and well-being of our nation’s youth,” Dr. Owens said. “By advocating for later school start times for middle and high school students, the AAP is both promoting the compelling scientific evidence that supports school start time delay as an important public health measure, and providing support and encouragement to those school districts around the country contemplating that change.”

In the February 2011 edition of Psychology Today, Dr. John Cline argues that later school start times alone really help high school students.

“So, do later school times really help high school students?” Dr. Cline asks. “Based on accumulating evidence, the answer is unequivocally yes. Increasing numbers of studies conducted in various parts of the country show that a change in the start time of the school day can make a significant positive change in the lives of  students.”

Dr. Cline notes that “many high school students live in what Dr. Mary Carskadon calls a continuous state of jet lag” and the key research suggests that “starting school later could help students get more sleep. Starting classes later, closer to when their biological clocks are most ready for learning, could make a real difference in how much knowledge a teen acquires at school.”

In a follow up article in May, Dr. Cline cited two key studies. The first by “Lufi, Tzischinsky & Hadar in a public school in Israel, showed that delaying the school start time resulted in students sleeping about 55 minutes longer per night than a control group kept on the usual early schedule.”

The second, “by Vorona and colleagues, compared two cities in Virginia with different school start times on motor vehicle accident rates between their respective students.”

The natural experiment tracks two communities close to each other in geography and with similar demographic profiles. However there is one difference – one of the school systems starts 75 to 80 minutes earlier than the other.

The authors reviewed DMV records for drivers between 16 and 18 years of age for 2007 and 2008. The accident rates for the community with the earlier start time “were 65.8/1000 in 2008 and 71.2/1000 in 2007 while the community with later start times had teen crash rates of 46.6/1000 in 2008 and 55.6/1000 in 2007. Differing degrees of traffic congestion were considered and did not account for the difference in crash rates.”

Dr. Cline argues, “There are several possible explanations for these findings. They include the possibility that less sleep for the students with an earlier start time results in poorer cognitive functioning due to problems such as slower reaction time.”

Starting time, of course, isn’t the only factor. Among the other factors were the use of electronic devices, which Madhavi Sunder told the Vanguard the district will seek to address as well.

“Our curriculum should make sure to educate children about good sleep habits and sleep science,” she said. “We need to educate parents on what they can do to help children fall asleep at a decent time. One very helpful recommendation shared at a recent DJUSD Parent Engagement Night was to turn electronics off an hour before bedtime — and to even ban electronics from the bedroom during sleep hours. We will need to take a holistic approach to this critical public health issue facing our teens and our society at large.”

—David M. Greenwald reporting

About The Author

David Greenwald is the founder, editor, and executive director of the Davis Vanguard. He founded the Vanguard in 2006. David Greenwald moved to Davis in 1996 to attend Graduate School at UC Davis in Political Science. He lives in South Davis with his wife Cecilia Escamilla Greenwald and three children.

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  1. Davis Progressive

    this seems like a done deal, seems like a lot of upheavel.  i’m still not convinced that a later starting time doesn’t mean kids stay up later on the phones and electronic devices and text their friends.

    1. Anon

      I’m with you on the issue of kids staying up too late on their techno-gadgets.  Not to mention the problems a later start time may cause working parents.  And a later start time does not prepare students for the working world, which often demands folks be at work very early.  Frankly (no, not referring to the poster named “Frankly”) I feel like this is a solution in search of a problem, to distract attention away from the real issues in our schools.

      1. Davis Progressive

        although if they set it to 8:30, it would be the same start time as the elementary schools, so i’m not sure that’s a huge factor.  the electronic gadgets is a bigger problem.

        1. Anon

          Agreed – the electronic gadgets are a much bigger problem.  I suspect an early start time is not really a problem.  So how would the school measure the success of such an experiment?  LOL What do you bet they don’t bother testing to see if a later start time makes any difference, or “creatively” interpret the data?

  2. Frankly

    I have two professional employees that do the same job.  One gets up at 5:30 am every morning and exercises and comes to work at 7 am and falls apart if she has to work late on a project.  The other can’t function will until 10:00 AM, and works nights and weekends.  Both are talented and intelligent.   The early-riser has greater academic achievement.  The late-worker is the more productive worker.

    I wonder sometimes if much of what we see in academic outcomes is connected to individual student biorhythms.  The early riser would have the advantage in the way our education system is structured.  Ironically in the modern economy the higher-paying jobs don’t require consistent early morning performance.

    1. wdf1

      Frankly:  I wonder sometimes if much of what we see in academic outcomes is connected to individual student biorhythms.  The early riser would have the advantage in the way our education system is structured.  Ironically in the modern economy the higher-paying jobs don’t require consistent early morning performance.

      Interesting that you reflect in that way.  I see the standardized testing regime (which you embrace) as ingraining a fixed-schedule, prescribed curriculum mindset.  I don’t think you see a connection between an abstract policy (accountability via standardized testing, prescribed curriculum and standards) and reality — observing that your academically-achieving employee may not necessarily be your ideally productive one.

        1. hpierce

          OK…maybe I’m “dense”… you support  “standardization testing”, with no apparent sanctions/rewards for educators “in lieu of an outcome-based pay-for-performance compensation system.” ? I can readily agree with the latter part, “pay-for-performance” in the public sector, but it appears you’re just looking for data.  I readily admit I might be missing your point.  Please consider elaborating.

    2. sisterhood

      Maybe she “falls apart “because you are asking her to stay late when she has a family or other personal life activities that you do not respect. Business owners often prioritize their family/spiritual life first, with their business a close second. She probably prioritizes her personal life first, and your business a not so close second.

  3. MrsW

    “the electronic gadgets are a much bigger problem”

    If teen biorhythms weren’t in the equation, I would agree with you more.  But many teens are awake late naturally, with or without the electronic devices.

    I see this as a public health issue, albeit a mental health one.  DJUSD is exhibiting leadership by doing what they can, or trying anyway, to combat student fatigue at school.  It’s like setting up a non-smoking area, but instead you’re setting aside a time of day.   Non-smoking areas didn’t stop people from smoking, but they were a start.

    1. MrsW

      I also want to point out that a start time between 8 and 8:30 is not radical.  I haven’t exhaustively researched all of the high schools DSHS competes athletically with, the the bell schedules for many of them run between 8 and 3:30.  As to those we consider our academic peers, who also have 7 periods — Palo Alto High School runs 8:15-3:25 or 3:35 each day; Berkeley High runs 8:27 to 4:34 each day; and Jesuit High school runs 8:15 to 3:00.  Lowell High School has 8 periods and runs from 7:35 to 3:30.

      1. sisterhood

        Does anyone know if North Davis still has the rule that no children are allowed on campus prior to school beginning? If so, I’d assume CDC will love any changes to the start time. More money for them. Does the school get any kind of kick back since CDC is located adjacent to North Davis?

  4. DavisBurns

    “Our curriculum should make sure to educate children about good sleep habits and sleep science,” she said. “We need to educate parents on what they can do to help children fall asleep at a decent time. One very helpful recommendation shared at a recent DJUSD Parent Engagement Night was to turn electronics off an hour before bedtime — and to even ban electronics from the bedroom during sleep hours. We will need to take a holistic approach to this critical public health issue facing our teens and our society at large.”

    I support the district in this effort.  In addition to turning off electronics a minimum of an hour before bedtime (3 would be better), they should educate students and parents about exposure to artificial light at night and the resultant delay or interruption of melatonin production.  While the blue spectrum light from electronics held close to the body may be the worst offender, it is not the only one. We should sleep in dark rooms with no night lights including glowing blue clock faces and blue “on” light indicators.  In my recently remodeled house even some of my outlets and wall switches glow constantly. If you want an electronic clock face, buy a red one and toss out the blue.  You want to block the light from street lights and neighbors UN-security lights as well (if they are shining in your windows, they are shining in the faces of people outside, constricting pupils, causing disability glare and decreasing security).  While these sources are further away, they still affect melatonin production by delaying the onset of production which is triggered by the absence of light or the interruption of melatonin production when you are exposed to artificial light during the night. There is ongoing research into how dim light needs to be not to interrupt melatonin production.

    Melatonin, a hormone produced by the pineal gland, is secreted at night and is known for helping to regulate the body’s biologic clock. Melatonin triggers a host of biologic activities. The body produces melatonin at night, and melatonin levels drop precipitously in the presence of artificial or natural light. 

    We are a diurnal species that evolved for millions of years with a blue sky in the day and a dark sky at night with red spectrum fire or moon light as the only illumination at night.  It is only the last 300 years that we have changed that and the human body is unlikely to adapt any time soon. Because we need both periods of light and darkness, the absolute denial of either is considered torture.

    Just one “pulse” of artificial light at night disrupts circadian cell division, reveals a new study carried out by Dr. Rachel Ben-Shlomo of the University of Haifa-Oranim Department of Environmental and Evolutionary Biology along with Prof. Charalambos P. Kyriacou of the University of Leicester.

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    “Damage to cell division is characteristic of cancer, and it is therefore important to understand the causes of this damage,” notes Dr. Ben-Shlomo. The study has been published in the journalCancer Genetics and Cytogenetics.

    The current research was carried out by placing lab mice into an environment where they were exposed to light for 12 hours and dark for 12 hours. During the dark hours, one group of mice was given artificial light for one hour. Changes in the expression of genes in the rodents’ brain cells were then examined.

    Earlier studies that Dr. Ben-Shlomo carried out found that the cells’ biological clock is affected, and in the present research she revealed that the mode of cell division is also harmed and that the transcription of a large number of genes is affected. She states that it is important to note that those genes showing changes in their expression included genes that are connected to the formation of cancer as well as genes that assist in the fight against cancer.

    “What is certain is that the natural division is affected,” Dr. Ben-Shlomo clarifies.

    From the National Institutes for Health:

    Many environmentalists, naturalists, and medical researchers consider light pollution to be one of the fastest growing and most pervasive forms of environmental pollution. And a growing body of scientific research suggests that light pollution can have lasting adverse effects on both human and wildlife health.

    When does nuisance light become a health hazard? Richard Stevens, a professor and cancer epidemiologist at the University of Connecticut Health Center in Farmington, Connecticut, says light photons must hit the retina for biologic effects to occur. “…it is not only ‘night owls’ who get those photons. Almost all of us awaken during the night for periods of time, and unless we have blackout shades there is some electric lighting coming in our windows. It is not clear how much is too much; that is an important part of the research now.”

    According to “The First World Atlas of the Artificial Night Sky Brightness,” a report on global light pollution published in volume 328, issue 3 (2001) of theMonthly Notices of the Royal Astronomical Society, two-thirds of the U.S. population and more than one-half of the European population have already lost the ability to see the Milky Way with the naked eye. Moreover, 63% of the world population and 99% of the population of the European Union and the United States (excluding Alaska and Hawaii) live in areas where the night sky is brighter than the threshold for light-polluted status set by the International Astronomical Union—that is, the artificial sky brightness is greater than 10% of the natural sky brightness above 45° of elevation.
    The 24-hour day/night cycle, known as the circadian clock, affects physiologic processes in almost all organisms. These processes include brain wave patterns, hormone production, cell regulation, and other biologic activities. Disruption of the circadian clock is linked to several medical disorders in humans, including depression, insomnia, cardiovascular disease, and cancer, says Paolo Sassone-Corsi, chairman of the Pharmacology Department at the University of California, Irvine, who has done extensive research on the circadian clock. “Studies show that the circadian cycle controls from ten to fifteen percent of our genes,” he explains. “So the disruption of the circadian cycle can cause a lot of health problems.”

    From Harvard Health Publications:

    While light of any kind can suppress the secretion of melatonin, blue light does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).

    Artificial light at night has become so pervasive access to darkness has become a privilege of the wealthy in this county. Exclusive communities in places like Boulder Colorado and Arizona offer dark skies as one of their amenities.  We now spend our vacations traveling to remote destination to experience the absence of light at night. People who think a move out of the city to a more rural setting will solve the problem are wrong.  Rural property owners have been taught glaring lights (the bigger the better) will keep them safe and they tend to think they are providing a community service by lighting the night as much as is possible.

    And least we think this is just a problem for humans, nocturnal and crepuscular wildlife suffer even more than humans when we subject their habitat to constant unremitting light during all the hours of darkness every day of the year. From the same article mentioned above:

    The ecologic effects of artificial light have been well documented. Light pollution has been shown to affect both flora and fauna. For instance, prolonged exposure to artificial light prevents many trees from adjusting to seasonal variations, according to Winslow Briggs’s chapter on plant responses in the 2006 bookEcological Consequences of Artificial Night Lighting. This, in turn, has implications for the wildlife that depend on trees for their natural habitat. Research on insects, turtles, birds, fish, reptiles, and other wildlife species shows that light pollution alters behaviors, foraging areas, and breeding cycles, and not just in urban centers but in rural areas as well.

    The school would do well to encourage their students to spend time outside during the day as exposure to the blue shifted light in the day increases alertness, improves their mood and helps with depression.

    In 20 years light pollution of public spaces will be as socially unacceptable as second hand smoke is today.

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