A later school start could help teens sleep more, feel better, and do better in class.
Many high school students struggle to fall asleep early enough to get proper rest before school. This is not simply a matter of habits. During adolescence, the body’s internal clock naturally shifts later, making teenagers feel awake later at night compared to adults. Because of this biological change, early school schedules often cut into the amount of sleep teens can get.
As the week goes on, the gap grows. Many students start off already tired, and repeated early mornings lead to a buildup of sleep loss over several days.
“This is concerning, as chronic sleep deprivation not only affects well-being, but also has a measurable impact on mental health, physical development, and the ability to learn,” says Oskar Jenni of the University of Zurich (UZH). Jenni, a developmental pediatrician, explains that teenagers are not able to fall asleep early enough to meet their sleep needs. He suggests that starting school later in the morning could offer meaningful benefits. While later start times have been studied widely, there is still limited research on flexible systems that let students choose when to begin their day.
Flexible School Start Times Put Teens in Control
To explore this idea, Joëlle Albrecht, Reto Huber, and Oskar Jenni from the University of Zurich and the University Children’s Hospital Zurich studied a school that adopted a more flexible approach. Three years ago, Gossau Upper Secondary School in the canton of St. Gallen introduced a system that allows students to adjust their schedules.
Students can attend optional modules before regular classes, during midday periods, or later in the afternoon. This setup gives them the ability to decide when to start their day. They can arrive at 7:30 am or begin at 8:30 am, when standard classes start.
The researchers used this change to examine how sleep patterns and sleep deprivation affected students’ health and academic outcomes. The students, who were about 14 years old on average, completed surveys twice. One was done under the old schedule, which started at 7:20 am, and another was conducted a year later, after the flexible model was introduced. In total, 754 responses were analyzed.
Later Start Times Lead to More Sleep
The results were clear. Ninety-five percent of students chose to start school later when given the option. On average, they began their day 38 minutes later than before.
This shift allowed them to wake up about 40 minutes later. Since their bedtimes stayed roughly the same, the later wake-up time translated into more total sleep. On school days, students slept an average of 45 minutes longer.
Students also experienced other benefits. “The students reported fewer problems falling asleep, and health-related quality of life increased,” says lead author Joëlle Albrecht. Academic performance improved as well, with better results in English and mathematics compared to cantonal test scores.
Better Sleep Linked to Improved Health and Learning
The findings, published in the Journal of Adolescent Health, suggest that flexible school start times could be a practical way to reduce ongoing sleep deprivation among teenagers. The results also indicate improvements in mental health and learning when school schedules better align with adolescent biology.
“Starting classes later in the morning can therefore significantly contribute to addressing the current mental health crisis among pupils,” says co-author Reto Huber.
Concerns about teen mental health are widespread. In 2022, the Swiss Health Observatory (Obsan) reported that 47% of 11 to 15-year-olds experienced recurring or chronic psycho-affective issues. These included sadness, fatigue, anxiety, low mood, tension, irritability, anger, and trouble falling asleep.
Reference: “The Power of Flexible School Start Times:” by Joëlle N. Albrecht, Alessa Risch, Reto Huber and Oskar G. Jenni, 17 February 2026, Journal of Adolescent Health.
DOI: 10.1016/j.jadohealth.2026.01.011
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