California has become the first state in the nation to push back school start times.

It will affect most public middle and high schools, which have three years to institute the changes, according to the L.A. Times.

It's a question that has lingered for years, pitting the research of what teenage bodies need vs. the reality of modern school schedules.

For the past several years, health experts — including those at the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatricians (AAP) — have emphasized the health benefits of a later school start time for older students. Because of hormones and other bodily changes, many teens have a harder time falling asleep at night and therefore a harder time dragging themselves out of bed in the morning. When they do get up, it's often after getting only a fraction of the nine plus hours of sleep they need to stay healthy.

California's law will set middle school start times at no earlier than 8 a.m. and high school start times at no later than 8:30 a.m.

The state follows in the footsteps of Seattle, which has been starting school later since 2017 and has seen positive results in students' academic performance and attention spans. The Seattle school district moved the start time from 7:50 a.m. to 8:45 a.m. for high schools. A survey of sophomore students from two schools found the median sleep duration increased by 34 minutes and that increase in sleep aligned with 4.5 percent increase in the median grades. One of the schools also noted fewer tardies and absences.

Chronic sleep deprivation in teens has been linked to an increased risk for obesity, higher levels of anxiety and depression, a greater likelihood of risky behavior, lower test scores and higher rates of drowsy driving. A study published in Sleep Health of more than 35,000 students found that with a school start time of 8:30 a.m. or later, teens were more likely to get the recommended hours of sleep. Teens stayed in bed about 46 minutes longer than their peers who started school earlier.

The domino effect

Students getting on a school bus in the morning Many school districts have carefully organized bus schedules to get kids of all ages to their elementary, middle and high schools on time. (Photo: Stuart Monk/Shutterstock)

Despite the health benefits associated with more sleep for teens, changing school schedules comes at a cost that some school administrators find too steep to accommodate.

Many school districts are reluctant to make the change, primarily because of money. Most school districts have a carefully choreographed bus schedule to get kids of all ages to their appropriate schools on time. Change the high school start time and you may need more buses or drivers to accommodate the change, adding up to hundreds of thousands if not millions of dollars depending on the district.

However, a study from the RAND corporation took a different approach, saying that switching to an 8:30 a.m. start time would outweigh the costs of delaying start times. The nonprofit research institution released a state-by-state analysis that showed a nationwide move to later school start times could add $83 billion to the U.S. economy within a decade. According to the corporation's statement:

The study used a novel macroeconomic model to project gains to the U.S. economy over 15 years from 2017, with this being around $140 billion by the end of the time period. On average, this corresponds to an annual gain of about $9.3 billion each year, which is roughly the annual revenue of Major League Baseball. The economic gains projected through the study's model would be realised through the higher academic and professional performance of students, and reduced car crash rates among adolescents.

One additional hour of sleep is, on average, estimated to increase the probability of high school graduation by 13.3 percent and college attendance rate by 9.6 percent, says RAND. This impacts their ability to get a job, to get a higher paying job, and to contribute to the economy down the line.

"For years we've talked about inadequate sleep among teenagers being a public health epidemic, but the economic implications are just as significant. The significant economic benefits from simply delaying school start times to 8.30 a.m. would be felt in a matter of years, making this a win-win, both in terms of benefiting the public health of adolescents and doing so in a cost-effective manner," said Wendy Troxel, senior behavioral and social scientist at the RAND Corporation.

A few hurdles remain

High school boys soccer team practice Keep the trickle-down effect in mind. If schools start later, after-school activities like sports will start later, and your evening family schedule may change, too. (Photo: Monkey Business Images/Shutterstock)

One solution that has worked in some districts is to keep bus schedules the same but swap the start times for elementary and high schools. An earlier start time might work better for younger students who are more likely to hit the hay earlier and wake up earlier each day. But this might also mean that little kids — who need at least 10 to 11 hours of sleep each night — may need to go to bed just after dinner. Logistically, it's never easy to alter the family schedule.

Another big issue affecting the decision to change school start times is sports. If schools start later, they'll presumably end later, too, giving students less time for after-school activities, including clubs, jobs and those all-important sports. Many student athletes already miss some school time to attend away games and practices. Moving the school day back means teens will miss even more school or face having to decide between sports and their studies.

But it's also just the idea of something different that's a problem. A peer-reviewed paper also published in Sleep Health looked at the fear of change as an obstacle to changing start times. They suggest that just offering scientific evidence for the advantages of later starts isn't enough to convince parents and administrators that later is better. Instead, they suggest apply behavioral-economic principles, like focusing on later start times as the norm rather than the exception, to make change easier.

Benefits all around

Teenage girl asleep in bed Well-rested teens take fewer sick days and are less susceptible to sports injuries. (Photo: PAKULA PIOTR/Shutterstock)

Some of the major advantages of the allowing students to get the amount of sleep they need each night is that well-rested teens take fewer sick days and are less susceptible to sports injuries. For school districts where federal funding is based on student attendance, fewer absentees could equate to hundreds of thousands or even millions of dollars in additional funds.

In work shared at the AAP National Conference, researchers found that student athletes who got at least eight hours of sleep each night were less likely than their sleep-deprived peers to get injured on the field.

So while students may have less time in the evenings for after-school activities, they may be able to make more out of the time they do have if they get a better night's sleep.

The financial and logistical hindrances to altering school start times are daunting, but considering the health benefits that could be gained, it seems California has the right idea.

Editor's note: This story has been updated since it was originally published in December 2016.

Why later school start times are a smart idea
Research suggests letting kids get more sleep can lead to healthier teens, better test scores and a stronger economy.