9:00 in the morning and Cassie is still
in bed most schools have already started
for the day but Cassie school now starts
later much later
it runs from half-past 1:00 in the
afternoon till 7:00 in the evening
waking up later and getting more sleep
has had a dramatic impact on life at
home I just get really annoyed by my mom
trying to wake me up I'm sorry but now
she doesn't really have to I can just do
it on my own I don't see her you know
looking tired and you know even if you
are dirty feel tired and you're likely
you know stroppy to summer better she's
much better they've changed the start
time at Cassie school not because they
think they're sick formers are lazy the
decisions based on more than 20 years of
research into the teenage body clock the
cards really are stacked against them
because they are overriding nature by
getting up quote early in the morning in
order to be it on time to school
overriding nature what is the science
here we asked the students to explain it
our body clock is located in the brain
in the hypothalamus and specifically in
the suprachiasmatic nuclei these cells
are responsible for all our 24-hour
timing systems in the human body in
adolescence as the brain continues to
grow and develop the body clock shifts
to two to three hours later a seven
o'clock start time for a teenager is
equivalent to a 4:30 wake-up time for an
adult I definitely think I'm less of a
classic teenager and in the mornings
I've been a lot more cooperative and a
lot nicer and I'll often be helping out
and I'll actually be doing chores out of
a want rather than a requirement in my
old school timetable I felt kind of
grumpy in the morning but then I would
wear out but now it's just I'm feeling
good all around because I've got good
sleep and good quality of sleep I find
it easiest concentrating lessons whereas
before it's sometimes we perform you
sleep in the over the first three hours
of the morning here it's
concentrate and just to focus on the
work that I have to do schools on a
day-to-day basis are dealing with a
whole range of issues sometimes mental
health issues I would argue there's a
public health issue really in terms of a
nation of teenagers particularly older
teenagers that are going to school
chronically sleep-deprived it's too
early to say if the changes here will
mean students do better in their exams
but it's hoped a wider study by Oxford
University will help other schools to
decide whether to change their timetable
Graham Satchel BBC News