SINCE 2022, California law has required high schools to begin no earlier than 8:30 a.m., a change backed by research showing that students naturally fall asleep later because of shifts in their circadian rhythms. But neuroscience professors say the change doesn’t serve everyone.
Teenagers vary widely in their biological sleep needs, according to UC Berkeley sleep researcher Matthew Walker. “Some teenagers’ internal clocks run longer than 24 hours, constantly pushing their sleep later; others have clocks that run slightly fast, making early mornings more tolerable.” Because of these natural differences, he explained in an email exchange, “one-size-fits-all school schedules inevitably disadvantage certain students through no fault of their own.”
Student-athletes especially feel the pressure. “Because practice takes up most of our day, it’s really hard to get enough sleep,” said Jacauiline Vega, a 10th grader at Heritage High School in Brentwood who balances water polo and schoolwork.
“If I sleep late one day, it affects my energy and focus for the whole week,” Vega said. “On days with sports, we get way less sleep than on others.”
“I usually get about seven hours on a normal night, but if I have a test, I’m staying up until midnight,” said Ayane Edmond, a 10th grader taking AP Chemistry and AP World. “This week was especially bad — almost every night I was up late studying. Teachers really should space out their tests instead of stacking them all in the same week.”
‘I’m basically annoyed at everyone’
For some students, the consequences of sleep deprivation show up immediately in class. “I get around seven to seven and a half hours,” said 10th grader Paulette Equihua Diaz, “but it really depends on how much work I have. Some days I go to sleep late or wake up early to finish an essay or assignment.”
In her core classes, Diaz said, “I’d get in trouble if I slept. But in classes like Ethnic Studies, they don’t really make it a big deal.” She added that teachers often assume it’s a time-management problem rather than a workload issue. “They’ll tell you to schedule your time better, but they don’t always consider that students stay up late because due dates are stacked.”
However, even with the school day starting a little later, many students at Heritage High say the lack of sleep affects their academic performance and mood. “I get irritated very easily. I’m basically annoyed at everyone,” Edmond said. “Sleep helps your brain process what you learn, so getting enough rest is crucial for remembering information for tests.”
Vega added that weekends allow some recovery. “On days off, I literally don’t wake up until 11 or 12, and I go to sleep late as well. I get a lot more sleep during weekends or vacations.”
But Mark D’Esposito, a neuroscience professor at UC Berkeley, said the “catch-up” method doesn’t work to perfection.
D’Esposito and his Berkeley colleague Walker — author of “Why We Sleep” — explain that the circadian rhythms of students predispose them to stay up late and wake up later. “You can’t really change someone’s biology,” D’Esposito said. “Some are morning people, some are night people. The key is to adapt to your natural rhythm.”
He emphasized the importance of a routine. “Seven hours is kind of a magic number. You also need to go to bed and wake up at the same time regularly. Poor sleep is a fixable problem,” D’Esposito said.
“It’s about changing habits, like leaving your phone outside the bedroom or avoiding late-night meals. Sleeping in on weekends to catch up doesn’t really work; maintaining a consistent schedule is better.”
Sleep deficit piles up
In an email exchange, Walker noted that “a week of partial sleep deprivation impairs a wide range of cognitive functions, subjective alertness, and mood, and some measures do not recover fully even after two nights of recovery sleep.”
Nellie Guerrero, the wellness counselor at Heritage High, noted that sleep is a frequent concern among students, coming up in around 80% of her daily conversations. She observed that many students are only getting 5-8 hours of sleep, far below the recommended 10-12 hours of sleep for teens. According to Guerrero, screen use plays a major role in this sleep deprivation, and with more use of electronics, the issue has worsened over the past two years.
SLEEP TERMS
Definitions of sleep terms from Cleveland Clinic:
- REM Sleep: The stage where the brain is highly active; mentioned in “Why We Sleep” as critical for learning and memory consolidation.
- Circadian rhythm: The body’s internal 24-hour clock, controlling sleepiness and alertness.
- Sleep debt: The buildup of lost sleep across several days.
- Partial sleep deprivation: Losing some sleep over several nights, which impairs cognition, mood and alertness.
- Recovery sleep: The sleep taken to try to make up for lost sleep, which does not fully restore cognitive function if deprivation has been ongoing.
Guerrero added that the 2022 school starting time shift did little to address the root cause, as students still don’t prioritize getting enough sleep.
The lack of consistency can be catastrophic, like “literally falling asleep during class in the morning, when students should be a little more awake,” said Maria Troelstrup, a Spanish 1 and 3 teacher at Heritage High. “Other times, students just seem distant or disconnected, slower to respond, or less likely to participate. I’ve noticed it increasing over the years — it’s enough to be a little worrying.”
Even small amounts of sleep deprivation can affect performance. “Sleep-deprived students process information slower, struggle to learn, and perform worse on morning tests than afternoon ones,” D’Esposito said. “If you’re missing even an hour of sleep a week, it starts to take a toll.”
For some Heritage High students, the challenge includes balancing the academic load. As student Ayane put it, “Honestly, if I could change one thing, it would be the homework. That is the main thing keeping me up.”
ShraddhaGouri Pallerla is a 10th grader at Heritage High School in Brentwood and a CCYJ reporter. This story originally appeared in CCSpin.