Many students have difficulty falling asleep early, which makes getting up for early classes a challenge. The reason for this lies in biology. During puberty, the body’s internal clock naturally shifts backward, meaning that teenagers feel more awake later in the evening than adults. Because of this shift, many teenagers cannot fall asleep early enough to get enough sleep before school. The problem often gets worse as the week progresses. Most teens start the week already sleep deprived, and the ongoing discrepancy between their biorhythm and early school hours causes sleep deprivation to accumulate over several days.

“This is concerning because chronic sleep deprivation not only affects well-being, but also has measurable effects on mental health, physical development, and learning ability,” says Oskar Jenni of the University of Zurich (UZH). Jenni, a developmental pediatrician, explains that teenagers’ natural sleep habits prevent them from going to bed early enough to meet their sleep needs. A later school start time could therefore offer meaningful benefits. Although the advantages of later school start times have been studied in many countries, there are few studies that examine flexible systems in which students can choose between earlier and later school start times.

Flexible Schedules Lead to More Sleep

Joëlle Albrecht, Reto Huber, and Oskar Jenni from the University of Zurich and the Children’s Hospital Zurich recently investigated whether more flexible schedules are better suited to the biorhythms of teenagers. Their research focused on the Gossau secondary school in the northeastern canton of St. Gallen, which introduced flexible school hours three years ago. Under this system, students can participate in optional learning modules before the official start of regular classes in the morning, during lunch break, or later in the afternoon. This approach allows students to decide for themselves when they want to start their school day. They can arrive as early as 7:30 a.m. or at 8:30 a.m. when regular classes begin.

The researchers used this change in the timetable to investigate how sleep habits and sleep deprivation affected students’ health and academic performance. The students, whose average age was 14, completed a questionnaire twice. The first survey took place under the previous schedule, when classes began at 7:20 a.m. The second survey was conducted a year later, after the flexible system had been introduced. In total, the research team analyzed 754 responses.

The results were clear. Ninety-five percent of students chose to go to school later when given the option. On average, they started their day 38 minutes later than under the previous schedule. As a result, students got up about 40 minutes later in the morning. Since their bedtimes remained largely unchanged, getting up later directly led to more sleep. On school days, the teenagers slept an average of 45 minutes longer than before.

The students also reported an improvement in their sleep quality and overall well-being. “Students reported having fewer problems falling asleep, and their health-related quality of life increased,” summarizes lead author Joëlle Albrecht. Academic performance also improved. Compared to cantonal test results, students scored higher in English and mathematics after the schedule change.

Better Sleep Promotes Health and Learning in Teenagers

The findings, published in the Journal of Adolescent Health, suggest that flexible school start times could be a practical way to reduce chronic sleep deprivation in teenagers. The results also point to improvements in mental health and academic performance when school hours are better aligned with adolescents’ biological rhythms.

During puberty, the biological sleep-wake rhythm of many young people changes. Their bodies produce the sleep hormone melatonin later in the evening, which naturally makes them tired later and requires them to sleep longer in the morning. Early school start times therefore often conflict with this biological rhythm. When adolescents still have to get up early, this often leads to permanently reduced sleep.

Starting school later can help reduce this conflict between social demands and biological needs. When young people have more time to sleep in the morning, they are more likely to get the recommended amount of sleep. Adequate sleep plays a central role in physical and mental health. Among other things, it supports emotional regulation, stress management, and concentration and memory skills. Young people who get enough sleep therefore report better moods, less irritability, and fewer symptoms of anxiety or depression more often.

In addition, starting school later can also have a positive impact on academic performance. Well-rested students are more attentive, can process information better, and are generally more productive in class. At the same time, the likelihood of concentration problems, fatigue in class, or absenteeism decreases. Studies also show that sufficient sleep supports learning and memory consolidation, which can lead to better academic results in the long term.

In addition to the health and academic benefits, a later start to the school day can also improve the general well-being of young people. When students suffer less from sleep deprivation, they feel more balanced in their everyday lives and are better able to cope with academic demands, social relationships, and emotional challenges. “Starting school later in the morning can therefore make a significant contribution to overcoming the current mental health crisis among students,” says co-author Reto Huber.

Strengthening Mental Health of Young People

Concern for the mental health of young people is widespread. In 2022, a report by the Swiss Health Observatory (Obsan) found that 47% of 11- to 15-year-olds show recurring or chronic psychoaffective symptoms. These include sadness, fatigue, anxiety, low mood, tension, irritability, anger, and difficulty falling asleep.

These symptoms are often interrelated and can reinforce each other. For example, sleep problems can lead to increased fatigue and irritability, while persistent worry or stress can make it difficult to fall asleep. In the sensitive developmental phase between childhood and adolescence, various factors also play a role, such as pressure to perform at school, social expectations, family stress, or the influence of social media. If such challenges persist over a longer period of time, they can significantly impair the emotional well-being of young people.

The findings of the report therefore highlight the importance of early support and preventive measures. Schools, families, and health and counseling services can play an important role in empowering young people and teaching them strategies for dealing with stress and emotional strain. Open discussion of mental health and low-threshold support services can help ensure that affected young people receive timely support and avoid long-term negative consequences.

How to Ensure a Restful Night’s Sleep

Several strategies can be helpful in getting enough restful sleep despite school commitments. An important factor is a regular sleep pattern. If young people go to bed and get up at roughly the same time every day – even on weekends – the body can better adapt to a stable rhythm. A consistent sleep schedule supports the internal clock and makes it easier to fall asleep and wake up in the morning.

The use of digital media also plays a major role. Smartphones, tablets, or computers before bedtime can make it difficult to fall asleep, as the blue light from the screens can inhibit the release of the sleep hormone melatonin. It is therefore recommended to avoid using electronic devices for about an hour before bedtime. Instead, quiet activities such as reading, listening to music, or relaxation exercises can help you unwind.

In addition, a comfortable sleeping environment contributes to better sleep. A quiet, dark, and rather cool bedroom promotes falling asleep and improves sleep quality. A comfortable bed and regular ventilation of the room can also help make sleep more restful. Another important point is physical activity in everyday life. Regular exercise—such as sports or walks—can help reduce stress and make the body naturally tired in the evening. At the same time, intense physical activity should be avoided immediately before bedtime, as it can activate the body in the short term.

Finally, dealing with stress and thoughts also plays a role. Young people are often under academic or social pressure. Relaxation strategies such as breathing exercises, journaling, or short meditation can help calm the mind before bedtime. Overall, it is clear that healthy sleep depends not only on the duration of sleep, but also on daily habits, the environment, and how stress is managed. If young people pay attention to these factors, they can significantly improve their sleep quality and thus also strengthen their well-being, mental health, and performance in everyday life.