Due to the ongoing COVID-19 pandemic, many Minnesota adolescents will be starting the school year in the next few weeks with distance learning. Since the logistics of busing and school sports are non-issues for virtual school, we would like to urge districts that are going remote to not require students to log in before 10 a.m.

The COVID-19 school shutdowns have provided an unprecedented, population-wide experience showing us how adolescents might naturally sleep, according to what their bodies need, were they not constrained by the artificial schedules imposed upon them by their high schools.

With last March's cascade of COVID-19 stay-at-home orders and schools being shuttered, Minnesota teens no longer had regular school days (or nights) for the final quarter of their school year. With online instruction being mostly asynchronous, students who slept well past what would have been their school's late bell could still log in and complete their daily assignments.

Was your late-sleeping teen being lazy? No, they were probably just sleeping in better accordance with their hardwired biology. The shutdown's "free sleep" days allowed them a schedule where they could get the rest their minds and bodies needed.

Adolescents need more sleep than adults. Most teens probably require just over nine hours of nightly sleep for optimal functioning the next day. This is in sharp contrast to what happens during a typical school year. For instance, we know nearly 80% of Minnesota high school juniors get seven hours or less of sleep on school nights.

Not getting enough sleep leads to bigger problems than just the unpleasant experience of facing the next day exhausted. The extreme chronic sleep deprivation that most American teens live with impacts their behaviors and mood, harms their health and jeopardizes their well-being. Sleep-deprived teens are at greater risk for mental health issues, suicide and injury from car crashes.

The main driver of teen sleep deficiency is the early start times of U.S. high schools, which are totally unaligned with teens' natural circadian rhythms. Neurobiologically, it is difficult for most teens, even those who put in a good-faith effort for an early bedtime, to fall asleep before 11 p.m. or wake before 8 a.m.

Is it possible that something as simple as delaying high schools' start times could confer substantial sleep benefits long-term? Our team used wrist sleep monitors to objectively measure sleep duration, timing and quality in Twin Cities metro-area high schools over multiple years. At the beginning of our study, all schools started early (7:30 or 7:45 a.m.), but after we began observing the sleep patterns of teens in these early-start schools, several of our high schools shifted their start times roughly an hour later, while the other schools maintained their early start time.

Students in the later starting schools got more sleep on school nights, even two years after the shifts to later starts. You might think that when schools start later, any benefit would soon be canceled by teens postponing bedtimes, but that's not what we observed. Students in the later starting schools went to bed at a similar time as students in the early starting schools. But the kids in the later starting schools got more sleep.

Further, most teens require extra sleep on weekends to pay back the "sleep debt" they run up during the week. In our study, we observed that students in schools that shifted to a later start time did not need to do as much catch-up sleep on weekends, underlining the reality that they were less sleep-deprived than their peers who attended early-start schools.

We should question how the schedules we impose on adolescents should and could be modified to enhance their well-being. We know that this coming year will be incredibly challenging and taxing on teens' mental health, with all the adjustments we will require them to make, with rite-of-passage experiences that may get skipped, and with isolation from peers.

Since sleep enhances the health and well-being for our children, let's push back against schedules that unnecessarily restrict it.

Rachel Widome is an associate professor of epidemiology and community health at the University of Minnesota (https://directory.sph.umn.edu/bio/sph-a-z/rachel-widome). Aaron Berger is an epidemiologist and a 2020 graduate of the University of Minnesota School of Public Health.