Teenagers aren’t lazy, Swiss study says their biology resists early school hours

The researchers concluded that teenagers' biological clocks run differently, and forcing them into early morning schedules may work against both their health and their ability to learn (Image: Canva)

• Flexible school start times gave teens 45 more minutes of sleep
• Students reported better sleep quality and improved wellbeing
• Later start times boost English and math scores.

Did our AI summary help?

For generations, bleary-eyed teenagers have shuffled into classrooms at dawn, clutching books and barely stifling yawns. Now, a recent research from Switzerland suggests the problem may not be teenage laziness at all, but simple biology.

Scientists at the University of Zurich say adolescents are naturally wired to fall asleep later at night. That biological shift in the body’s internal clock means early school mornings often clash with teenagers’ natural rhythms, leaving many students chronically short of sleep throughout the week.

To explore whether a different timetable might help, researchers studied a Swiss secondary school that introduced flexible start times. Students could begin their day earlier with optional modules or arrive later when regular lessons began, effectively allowing teenagers to choose when their school day started.

Also read | 6 healthy habits to make your teenage child calmer, happier, emotionally intelligent

The research team analysed surveys from 754 pupils aged around 14 at Gossau Upper Secondary School in the canton of St. Gallen. The first survey was conducted when school began at 7:20am. A second survey took place a year after the flexible system was introduced.

Flexible mornings, clearer minds

According to the result, when given the option, an overwhelming majority of teenagers chose to begin later. On average, pupils arrived nearly 40 minutes later than before, and their bodies seemed to thank them for it.

Here’s what the researchers discovered

Most students preferred a later start: When schedules became flexible, about 95 per cent of pupils opted to begin the school day later rather than attend early morning modules. Teenagers clearly gravitated toward timetables that matched their natural sleep patterns.

Students gained almost an hour of extra rest: With later start times, teenagers woke up roughly forty minutes later in the morning. Because their bedtimes remained largely unchanged, the shift translated directly into about 45 additional minutes of sleep on school nights.

Also read | Teenage obesity: 6 ways weight gain affects the brain and emotional health

Sleep quality improved: Students reported fewer difficulties falling asleep and described better overall rest. Researchers also observed improvements in general wellbeing, suggesting that a modest timetable adjustment could help reduce the persistent fatigue many adolescents experience during the school week.

Wellbeing and health indicators rose: Teenagers taking part in the study reported improvements in their health-related quality of life. Researchers believe the extra sleep helped reduce stress and fatigue, both of which are known to affect mood, emotional balance and day-to-day resilience.

Academic results were improved: After the flexible schedule was introduced, students achieved better scores in English and mathematics compared with cantonal test benchmarks. The researchers suggest improved concentration and mental alertness may explain the academic boost.

The findings may address wider mental health concerns. Researchers believe later start times could help tackle growing worries about adolescent mental health, particularly as many young people report recurring symptoms such as fatigue, anxiety, irritability and low mood.

Researchers suggest that the teenagers are not miniature adults. Their biological clocks run differently, and forcing them into early morning schedules may work against both their health and their ability to learn.

Flexible school start times, the study concludes, could offer a practical solution, one that gives teenagers a little more sleep, a little more clarity in the classroom, and perhaps a healthier start to the day.

Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis.