By Hannah Richardson
Many parents struggle to get their children out of bed in the morning
University of Oxford researchers say teenagers start functioning properly two hours later than older adults.
A trial tracking nearly 32,000 GCSE pupils in more than 100 schools will assess whether a later school start leads to higher grades.
Improved mental health and wellbeing could also result, the scientists say.
Professor of sleep medicine Colin Espie said: "Our grandparents always told us our sleep is incredibly important.
"We have always known that, but it's only recently that we've become engaged in the importance of sleep and circadian rhythm.
"We know that something funny happens when new teenagers start to be slightly out of sync with the rest of the world.
"Of course, your parents think that's probably because you're a little bit lazy and opinionated, if only you got to bed early at night, then you would be able to get up early in the morning.
"But science is telling us, in fact there are developmental changes during the teenage years, which lead to them actually not being as tired as we think they ought to be at normal bedtime and still sleepy in the morning.
"What we're doing in the study is exploring the possibility that if we actually delay the school start time until 10am, instead of 9am or earlier, that additional hour taken on a daily dose over the course of a year will actually improve learning, performance, attainment and in the end school leaving qualifications."
