Many high school students find it difficult to fall asleep early, making it difficult to wake up for early morning classes. The reason lies in biology. During adolescence, the body clock naturally shifts later, so teenagers tend to wake up later at night than adults. Due to this change, many teens are unable to fall asleep early enough to get enough rest before going to school.
As the weeks go by, the problem often gets worse. Most teens already start the week sleep-deprived, and the continued mismatch between their biological rhythms and early school schedules allows sleep deprivation to accumulate over several days.
“This is worrying because chronic sleep deprivation not only affects health, but also has measurable effects on mental health, physical development and learning ability,” said Oskar Geni from the University of Zurich (UZH). Jenni, a developmental pediatrician, explains that teens’ natural sleep patterns prevent them from going to bed early enough to meet their sleep needs. Therefore, allowing school to start later in the morning could have meaningful benefits. Although the benefits of later start times have been considered in many countries, few studies have looked at flexible systems that allow students to choose between earlier or later start times.
Flexible school start time test
Joëlle Albrecht, Reto Huber and Oskar Jenni from the University of Zurich and the University Children’s Hospital Zurich recently investigated whether more flexible schedules are better suited to teenagers’ biological rhythms. Their study focused on Gossau High School in the northeastern state of St. Gallen, which introduced flexible class times three years ago.
This system allows students to participate in optional study modules before the formal start of regular morning classes, during the midday break, or in the late afternoon. This approach allows students to decide when to start school. You can arrive as early as 7:30 a.m. or start at 8:30 a.m., when regular classes begin.
Researchers used this schedule change to examine how sleep patterns and sleep deprivation affect students’ health and academic performance. Students with an average age of 14 years completed two surveys. The first survey was conducted as scheduled, at the start of school at 7:20 a.m. The second survey was conducted one year after the introduction of the flexible system. The research team analyzed a total of 754 responses.
Flexible schedules increase sleep time
The results were clear. 95% of students chose to start school later if given the choice. On average, I started my day 38 minutes later than my previous schedule.
As a result, students woke up about 40 minutes later in the morning. Their bedtimes remained the same, so they slept longer by waking up later. On school days, teens slept an average of 45 minutes more than before.
Students also reported improved sleep quality and overall health. “Students reported fewer problems falling asleep and improved health-related quality of life,” summarizes lead author Joel Albrecht. My academic ability has also improved. Compared to state test results, students performed better in English and math after the schedule change.
Better sleep supports youth health and learning
The survey results are Youth Health Journalsuggests that making school start times more flexible may be a practical way to reduce chronic sleep deprivation in teens. The results also show that when school schedules better match adolescents’ biological rhythms, their mental health and academic performance improve.
“Starting classes later in the morning could therefore significantly contribute to addressing the current mental health crisis among students,” said co-author Reto Huber.
Concerns about the mental health of young people are widespread. A 2022 Swiss Health Observatory (Obsun) report found that 47% of 11- to 15-year-olds experience recurrent or chronic psychoemotional symptoms. These include sadness, fatigue, anxiety, low mood, nervousness, irritability, anger, and difficulty falling asleep.
