New European research has found that giving teenagers a more flexible start time at school could help them get more sleep.
Led by researchers at Maximilian University in Munich, Germany, the new study looked at 102 students aged 15 to 19 years old.
The team monitored the participants' sleep for three weeks before introducing a new flexible start time at their school, which allowed them to choose between an 8 a.m. or 9 a.m. start each day, and six weeks after.
The teenagers were required to record their sleeping patterns each day, with 65 asked to use a daily diary, and 37 wearing a wrist device that measured movement and periods of activity and inactivity.
At the end of the study, the participants reported their overall level of satisfaction and their ability to concentrate in class and while studying.
The findings, published in the journal Sleep, showed that at first, the students made little use of the new flexible schedule, and chose to start school later just twice a week, which surprised the researchers.
However, on the days they did the later start time, the students slept for more than an hour longer than usual, regardless of their gender, grade, chronotype (whether they were naturally an 'early bird' or 'night owl') which the researchers say shows the benefit of a later school start time.
The students also reported being very satisfied with the new schedule, with the vast majority saying they slept better and were better able to focus on their studies.
"Perhaps the very fact that one can decide for oneself when to get up in the morning is sufficient to break the cycle and reduce the pressure," said co-lead author Eva Winnebeck.
The authors added that "flexible systems are a viable alternative for implementing later school starts to improve teenage sleep," noting that actively encouraging students to make use of the later start time is also important.