Kate Hawkesby: Teens live in a different time zone so let them start school later

Science suggests we should let teenagers start school later in the day.

COMMENT: For us early risers, the benefits of being up before dawn reveal themselves not long after we turn the alarm off.

According to research, getting up early makes you happier, more productive, more conscientious, better at exercising - and for women a study out of Bristol University says it can reduce the risk of breast cancer.

A lot of it, we learn, comes down to our DNA. Because night owls (those who go to bed and get up later) have fundamental differences in their brain function compared to 'morning larks'.

The University of Birmingham Centre for Human Brain Health found that those with a body clock which sees them go to bed later, and wake up later, are likely to suffer "poorer attention, slower reactions and increased sleepiness throughout the hours of a typical working day".

I found this fascinating given all the talk recently out of the UK about letting teenagers sleep in longer and start school an hour later so they can get the rest their teenage body clock requires.

Anyone with a teenager knows what a struggle mornings are - they're not exactly naturally high functioning animals first thing.

Sleep experts in the UK recently urged authorities to alter school hours to allow adolescents to stay in bed longer. They cited benefits to their mental health, to attaining better results, and to combat obesity.

Nothing, it turns out, beats sleep. They're doing it in Paris of course - France's education minister approved pushing the school day back an hour for teenagers.

But it's not just the kids who'd like, or in fact need, a longer sleep-in.

Teachers and school leaders often complain about how tired teens are in class, how lacking in concentration they are first thing in the morning. And that's not entirely teenagers' fault.

Scientists say that our circadian rhythms change in adolescence - it's a shift of about two hours - which means teens become wired to go to sleep later.

One paediatric sleep consultant says teenagers are "in a different time zone".

So given that, and given the importance of sleep for their health, delaying the school day by an hour would seem an obvious thing to do.

But - and there's always a big 'but' here - what happens when they start work?

What happens when tired teens are out of school and have never learned to get themselves up earlier than 8 or 9 o'clock - and they're expected to function in the working world?

Not to mention the disruption for families of changing timetables around to suit teenagers. Hitting snooze for an extra hour just to pander to teenagers' altered circadian rhythms doesn't necessarily work for everyone.

So perhaps if a sleep-in is off the cards schools could take note and maybe just not schedule double maths first period.