If you’ve got a tired teen on school mornings, don’t blame the teen, blame their early morning class. That’s the message out of a recent science conference in the U.K. Apparently teens are running on a daily sleep deficit because their bodies aren’t wired to wake up at the time that schools require them to.

University of Oxford researcher Paul Kelley spoke about a study, which he co-authored using 30 years of research, saying the modern school system creates a daily two- to three-hour sleep deficit for teenagers. Based on the growing body of evidence, he and his colleagues suggested the following school start times:

- At the age of 10, the biological wake time is about 6:30 a.m., so a school start time of 8:30 to 9 a.m. would make sense.

-At age 16, that wake time has shifted to 8 a.m., a time when many students are expected to be at school or at least en route. Kelley says a better time for the morning bell would be 10 a.m. or later.

-At age 18, the wake time has shifted even later, to 9 a.m., so an 11 a.m. or later start time would be ideal for post-secondary schools.

Biology rules
Kelley explains that, during adolescence, two biological changes intersect to cause the disconnect between teens’ natural wake times and school start times. Teens still need about nine hours of sleep, but their inner clocks shift. Kelley writes that a teen can’t simply turn out the lights and go to bed earlier; the system that regulates the impulse to sleep overrides even the strongest parental command.

Since sleep loss is known to have negative health consequences, such as increasing the risk of car crashes, reducing academic performance and impacting immune response, diabetes risk, blood pressure, chance of obesity and mental health, this disparity in wake times is a serious concern.

Some schools are already experimenting with healthier schedules. In a study out of North Carolina, starting school an hour later translated into a two percent increase in math and reading scores. The benefits were strongest for kids who usually had the lowest test scores and those higher marks lasted at least two years, Kelley writes in the study.

"The science explicitly shows that many people are suffering unnecessarily because of our work and study start times. There’s no real rationale for start times for schools so there’s a huge opportunity here to improve quality of life by putting these scientific findings into practice," he said at the conference, reports the Irish Times.

Sounds like perfect fodder for your next school council meeting. And your teen will thank you for it!

For more tips on how to regulate your teen’s sleep cycle—and your own—read on.