Secrets of the Body Clock with Terry Wogan

Throughout my life on radio and television,

I've had to do things, not just by the book, but by the clock.

It's 18 minutes to 10:00.

Whether it's managing the precise timings of a radio show...

or the unstoppable deadlines of live TV...

Only 35 minutes to go.

..the rigours of the clock has ruled everything I do.

But not just me.

For all of us, the time we wake, the time we eat, the time we sleep,

the time we play, is dictated by modern life.

We all seem to be in such a rush, constantly running out of time.

One in five of us now do shift work,

all to provide everything 24/7 society demands.

Just to keep it ticking along.

But odd as it may sound, there's another clock ticking.

It's a biological clock. The human body clock.

We ignore it at our peril.

Tonight, we reveal that inside every one of us is a ticking clock.

A body clock which dictates when we should

and shouldn't be doing almost everything in our lives.

If you go to the gym early morning or late at night,

you might need to think again.

Have you ever wondered why alcohol affects you more at lunchtime?

Understand the body clock and you'll understand why.

I've found my vocation at last. Pouring drinks.

Now, incredibly, there's a best time for you to go to work,

drive your car and even go to the dentist.

Want to know why?

Well, stick with me and you'll find out.

This is the ultimate guide to the body clock.

The first thing you have to do

is to find out what kind of a body clock you have.

Are you a lark, or are you an owl?

A little thing you can all do

is to think about what time you like to get up in the morning,

rather than what time you have to get up.

ALARM

Generally like to get up at about 9:00am.

Any later than that, I feel like I'm wasting time in bed.

5:00am.

2:00, I'm quite lazy.

I actually don't feel human until about 10:00.

Most people instinctively know if they're a morning

or a late-night person,

but now I'm going to take a more scientific approach

to find out the timing of my body clock.

Have a look at these.

These are test tubes, as you can see.

Even the untutored eye can make out a test tube.

And the thing is, that this is a kind of spitting contest.

I've got to spit into one of these

every half-hour from now, 7:00,

until I go to bed, which is 11:30, and then an extra half-hour, 12:00.

So it's going to keep me awake, spitting.

My saliva will be tested to find the time

I start to release a hormone called melatonin.

Its release is controlled by the body clock

and it tells the body it's time to sleep.

That's about it. I'm out of spit.

I hope this is worthwhile.

I may never live it down.

# Wake up, it's a beautiful morning

# Feel the sun shining for your eyes. #

Now I'm semi-retired,

I have more choice about what time I do all sorts of things,

including waking up and getting out of bed.

Nowadays, I like to be up and about around 8:00.

I'm more or less on me toes as soon as I get out of bed.

And when I stay with some friends,

they used to find it got on their nerves a bit

because they were the kind of people who didn't come to

until they'd had their first cup of coffee or a slice of toast.

And there am I, smiling and cheering,

thinking, of course, I'm doing good,

and all I'm doing is irritating people.

And then I made a living by irritating people.

Quite extraordinary.

It's results day.

Time to find out if I'm a morning lark due to habit

or because of my biology.

We found out that you are, what we would call, a semi-lark.

So you're not an extreme morning type,

you are a sort of moderate morning type person.

There you are. I thought I was more of a sparkler in the morning

and you tell me I'm slightly less than larky.

Not completely extreme.

I think if you were complete extreme,

fine, you would be fine very early in the morning,

but you wouldn't be able to make it past 9:00 in the evening.

So here we have your melatonin levels.

-So this blue line...?

-Yeah.

For every half an hour that you did for us.

I seem to be at a very low level here. Is this a good or a bad sign?

Ah, well, as one gets older,

the amount of melatonin that's produced is less.

-So, this blue line is a decrepit old geezer?

-Not at all.

We're more interested in the time that it begins to rise.

If you had an early clock, you would rise here.

If you had a late clock, like this person here,

you would rise a lot later.

So this tells us that you've got a clock

that's rising at about 11:00 in the evening

and that is, you know, fairly normal.

Is it better to be a lark than an owl?

There's no judgment on that.

I think you've got to know what you are

and then choose to hopefully be able to choose your life

to live in that sort of mode.

Crucial question. What is a body clock?

A body clock is a system that tells our body what time of day it is.

It makes you alert during the day

and importantly, it tells you when you should sleep.

Deep in the middle of our brains, we have a main clock.

Two small nuclei called the SCN or suprachiasmatic nuclei.

And they pulse out a regular rhythm.

That's literally tick, tick, tick.

And we know from different studies

you could take that out of the body

and it literally can oscillate or tick.

It's a clock you could put in a dish.

-It ticks.

-That's pretty frightening.

It is. Do you find it frightening?

There's something vaguely alien about that.

Well, it's there and it's all...

It's a master conductor of a clock system.

The SCN body clock helps to co-ordinate

the release of crucial hormones, like melatonin,

which affect the body's functions at different times of the day.

So, what activates the clock system? Is it going all the time?

Yeah. It can generate itself.

It's...it's like your watch.

Without a battery, it keeps ticking and ticking,

but it ticks at different speeds.

And so what we do need is light through the eyes,

light from the lights outside.

And the light signal goes to the clock and says,

"It's daytime. It's night-time.

"It's daytime. It's night-time."

So that clock gets information from the environment.

So because melatonin causes sleepiness,

if your melatonin level rises early in the evening,

you're likely to go to sleep earlier than other people,

which will mean you'll probably wake up earlier, as well.

I'm not as larky as I thought I was

and I'm lark with owlish tendencies.

I suppose that's what makes me more of an all-round person.

So my clocks are not bad, they mean that I can get up in the morning

and I can stay up at night until I fall over.

So I'm happy with my body clocks.

Give us a smile, Terry.

No, no. No, he's a much younger man.

-Oh, God!

-LAUGHTER

Absolutely not. You're fired. Are you the lecturer?

No, no, of course. Come on.

Debra's tests also reveal that my melatonin levels are relatively low.

This is going to absolutely crucify your street cred.

And I'm told the less melatonin can mean a body clock

that doesn't keep time as well as it could.

It's typical of people of a certain age

and means we often wake up during the night.

I'm going to see if there's anything we oldies can do about that.

I've come to the Anisha Grange care home,

where the residents are exploring ways to keep their body clocks healthy

by ensuring good sleep patterns.

It's research that could actually benefit all of us.

Tea and biscuits.

Can I persuade anybody to a dish of tea and a little biccie?

So ladies first, I imagine. Who...?

-I don't like tea.

-You don't like tea?

-No.

-I'll go out again.

LAUGHTER

-What about a gin and tonic, missus?

-Yes.

-Lovely.

Meeting me here to tell me more about research

into our body clock is Dr Benita Middleton.

So, Benita, I hear that my body clock is changing as I get older.

Yes. As everybody ages, the body clock inside our brain changes.

And one of the main factors that influences this

is the amount of light that we see.

Research has shown that when light hits the back of our eyes,

it causes the body clock to suppress the sleep hormone melatonin.

And that makes you more alert.

They've even found out that the colour makes a difference. Would you believe that?

The best, apparently, is blue light because it mimics daylight.

As you get older, the structure of our eyes changes.

So when you're young, you have a nice, clear, thin lens like this,

-which lets a lot of light through.

-I can see you clearly.

But when you get older,

your lens gets thicker...

like this...

..so you get a bit less clarity.

And also, it builds up yellow crystalline deposits, like that...

which cuts down even more light.

Specifically, the short wavelength blue light,

which is most important for the body clock.

Would I be at that stage? Am I at the yellowing stage?

Most definitely, yes. I mean...

No need to be most definite about it.

Well, you see, it starts reasonably young.

So when we're born, the lenses in our eyes are perfectly clear,

but as we get older, they start to change colour.

So that by the time you reach your 20s,

they're already beginning to look a pale yellow.

By 40, the colour is very pronounced, definitely yellow,

and if you live to 90, they might appear almost brown.

A lot of research has taken place

looking at increasing light levels within the care homes

to see if we can improve their sleep/wake cycle.

The Anisha Grange care home has been designed

to let in as much light as possible,

but they've also been trying out these little blue lights.

And then you have it on in the morning, Jim, for up to four hours.

Oh, I see.

Using lights like these can help our body clocks keep proper time,

meaning people nap less during the day,

sleep better and longer during the night.

Hopefully, the lights will improve life for these residents.

Well, that got me thinking about the light levels in my own home,

so I've come back to take a proper look

and see how much light I'm actually getting.

This is my favourite room. I sit here more often than not,

watch the television, read a book.

This is a lux meter.

This enables me to find out exactly what the light is like in here.

It's 54 lux.

Not very high. So let's go outside and see if it's any higher.

It is a fairly dullish old day,

but, er...I'm going to check and see what it is.

Ha! Virtually 12,500 lux units.

Thousands and thousands more

than it was in what we thought was a reasonably-lit room indoors.

It's extraordinary.

So you're sitting in what you think is a reasonably-lit room

and in fact, you're in the gloaming.

You....you're almost in the dark,

but you don't know it. But your body does.

I hate to tell you, but our busy lives mean

most of us are getting less than one hour of daylight a day.

So if we want to keep our body clocks healthy,

we need plenty of light.

Leaving our gloomy offices and taking a walk at lunchtime

can be enough to make a big difference.

But for some people, it's not quite so straightforward.

Justin McCloud has never been able to see light.

Tell us about your condition.

Well, I suffer with what's called anophthalmia,

which is where I'm born without eyes, have no eyes at all,

so I wear artificial eyes, which is great fun at parties.

And I took them out for my oldest godchild

and he was like, "Wow! Do it again!"

Justin's condition has a serious impact

on his sleep patterns and sense of time.

It frustrates the hell out of my mum, um...

with...with whom I live,

because often I'm just going to bed

when she's getting up for work in the morning.

I really have to force myself to be a normal-sleeping kind of person.

You're doing things at peculiar times all the time.

Yeah. You know, I've been known to, um...

If it's a nice, warm night,

I've been known to go out to the park

at about 3:00 in the morning.

We've got a park literally, almost, right outside our house.

Um...cooking is the main one.

My mealtimes, because of my sleep times,

are completely, um...off-kilter.

He'll be up at sort of 4:00 in the morning cooking dinner.

I can wake up at 6:00 in the morning ready for work and think,

"I think I can smell a dinner.

"I think I can smell a chilli con carne or something."

How does it affect your life, your everyday life?

Well, I'm an aspiring sound designer.

I'm on the board of trustees for a small online charity.

And that's really rewarding and really good fun.

To sort my sleep pattern out would be lovely

because then I'd get more done all-round.

And that's exactly what researchers are trying to do

here at the John Radcliffe Hospital in Oxford.

For the body clock to be of any use,

it has to be hit by light every day to set it,

to stop it drifting through time.

Here's a single day here represented with 24 little strips.

Here's when we're asleep, this is when we're awake.

And normally...

this is beautifully aligned

because most of us are seeing the light/dark cycle, dawn and dusk,

and so every day, our sleep is pretty stable.

It occurs about the same time.

In Justin's case, he's lacking that daily resetting cue.

And so what happens is that he will get

a little bit later and later and later each day.

And you can think of that as a bit like

unremitting jet lag for the rest of his life.

And why we're studying Justin is to try and find out

if we can correct that drifting, free-running body clock.

And has he any hope of readjustment,

of having a balanced life,

or getting his body clock back in balance?

There are ways in which you can, you can hit the body clock

with various chemicals.

And...and...and so the body clock thinks it's night and day.

That's what we're moving onto next.

We're going to try some drugs

which will give the body clock its sense of time again, hopefully.

I'm astonished at this research into the body clock.

And what's more, Russell says

he's able to show me my own body clock in action.

It's slightly daunting, but I'll be plucky.

While I'm lying in this giant metal tube,

I'm being shown a series of bright images

which should reveal my body clock reacting to light.

The things I do in the interests of neuroscience.

Oh, hang on.

Ah! Now I can hear at last.

So, Russell, what we have here is the results.

Yes. And you'll be pleased to know that this is, in fact, your brain.

This bit of the brain is the visual cortex.

And you see that in response to light, it's lighting up.

Just to give you some sense of that,

here is a brain, a model of a brain,

and it's this bit at the back here.

So sometimes if you're hit on the back of the head, you see stars.

Because you're actually hitting that bit of the brain.

Extraordinary. So, that's at the back of the head?

Yeah. So let's now go on to look at the clock areas of the brain.

This is the visual area of the brain,

now we're going on to the clock area of the brain.

And what we'd expect, of course, is when we turn the lights on,

your eye would deliver light information

to the master body clock.

So this is the area of the brain that's sort of lit up.

And that's the activation of the suprachiasmatic nuclei.

That's, of course, how the clock can be aligned

to the environmental light/dark cycle,

which stops you drifting and getting up later and later and later.

So the eye is doing two fundamentally different things.

Of course, the accepted function of the eye,

which we've known for 150 years, you've built an image of the world.

And yet there's this other function

which is entirely independent, if you like,

which is giving an overall impression of brightness to our brains

and our body clock, in particular.

It was interesting to undergo the scan.

And it's reassuring for me

because lots of people tell me I'm not the full shilling.

I was able to see from the scan that there is a brain in there.

It may not be working all that well,

but it lights up at the right time.

And it's been an extraordinary revelation to me.

Is there even more stuff

that we have to find out about ourselves that we didn't know?

And I'm perfectly sure there is,

because we're only just beginning with this body clock.

You'll be amazed what I've been finding out.

ALARM

According to our body clocks,

just after waking up in the morning

is the best time for men to have sex

because their testosterone levels are at their highest.

I think I can remember that.

And you're not going to believe this,

but morning is also a very busy time in the maternity units.

-Good.

-Come on, push harder.

Most babies are born between 6:00 in the morning

and 1:00 in the afternoon.

Come on, push down. Down, down.

This is because our body clocks make us relaxed at night.

And being relaxed is good for the onset of labour.

A few hours later, this is the result.

There's a body clock regulating when she wants to eat,

when she wants to sleep.

Any of her bodily functions.

From the day we're born, our body clock controls our lives.

A newborn can only eat a little bit at a time.

And these babies' clocks wake them up every few hours so they can feed.

As babies grow, they soon start to sleep longer in the night

than they do in the day.

But it isn't until we reach about five years old

that our body clock is in tune with that of an adult.

In one of those strange coincidences that life throws at us,

the morning is also the most likely time that we die.

Just to cheer you up(!)

At this time, our body clocks are revving us up for the day ahead.

So there are lots of changes that go on

and these are principally driven by hormones,

but our blood pressure starts to rise,

there's a change in our heart rate,

there's a change in the tone of our coronary arteries

and there are changes in the stickiness and viscosity,

the thickness of our blood.

So our blood is more prone to clotting, to forming blood clots

during those first few hours of the morning.

So all of those things can join together

and in a vulnerable patient

who has got a problem that's already established,

put them at risk of developing a heart attack or a stroke

at that particular time of the day.

So, would you say, then, that in your experience here

that more people die or get heart attacks in the mornings

than do in the afternoon and the evening?

Yeah, I think that's definitely true.

There's a very clear peak in the very first three or four hours after waking,

from about 6:00 in the morning through close to midday.

And, er...many series have reported a doubling

of the rates of heart attacks in those times.

So the best thing to do is when you get up in the morning,

hang tough and do your best to stay alive

through the middle of the day and you'll make it to the evening.

Yeah, to a degree.

But I think more important than that is to make sure

you're not in that situation where you're vulnerable.

So if you do all the right things

and you exercise regularly and you eat sensibly

and you see your doctor for intermittent checks and, er...er...

you give yourself really strong protection,

you shouldn't fear the vulnerable period first thing in the morning

because it won't be relevant.

One thing is clear from my conversation with Will,

prevention is better than cure.

So on doctor's orders, it's time for some exercise.

What time do we like to tread the mill?

I wake up at 5:00 so I can exercise in the morning.

Generally, I like to go before work.

Ooh, I think first thing in the morning

when I go swimming or I go for a walk.

It looks like many of us are fitting in our exercise before going to work.

Gyms all over Britain open their doors at 6:00 in the morning.

But is this really the best time?

This is the National Tennis Centre in Roehampton.

The perfect place for some professional advice.

Exercise is going to feel a little bit easier

in the late afternoon and early evening.

And it's going to feel a little bit harder in the morning.

Partly, that's because your body temperature is rising through the day

and that facilitates things like muscle function and so on.

And so you're able to perform a little bit more.

But if you exercise too late, that will impair your sleep quality

-and knock out your body clock a little bit, as well.

-Oh, I see.

I don't know about you, but I find it remarkable

that my body clock even has an influence on my temperature.

Changing it throughout the day to suit expected activity levels.

Ideally, I wouldn't play tennis before 11:00 in the morning

if I could have it my way every day,

but you have no say in the schedule,

so you've got to be able to adapt

and be ready to play whenever that's asked of you.

In your experience, what was the best time of the day for you?

Late afternoon. Definitely late afternoon, yeah.

Are you an early riser?

I am, yeah. I like getting up in the morning, I think, but I just...

I think you always feel that much sort of looser in your body

and sort of more energetic.

It gives you more time to put everything in place during the day

and I think your body's naturally sort of more active at that time,

sort of, any time, 3:00, 4:00, 5:00 or 6:00 in the evening,

-but not the night matches.

-No.

The night matches are a little tougher.

That's perfect.

I'm starting to appreciate just how much influence

our body clock has on our daily activities.

I'm astonished that our bodies, inside...

Although we appear to be in charge of everything,

we can do what we like, go to sleep when we like,

wake up when we like, do everything because we're in charge, we're not.

These little clocks whirring away, oscillating, ticking in our bodies,

impossible as it is to believe,

they're the ones who are taking the decisions for us.

For example, although not a natural striker of the ball,

I like the odd round of golf.

And now I can play any time, well, I tend to play in the afternoon.

Shot.

Do you know, I thought I'd nearly lost my tee there, Brian.

-Close the course.

-An expensive old game.

I hadn't realised that decision

was down to the influence of my body clock

guiding me when to exercise.

And when to concentrate, too.

Apparently, the best time to use your brain is mid-morning,

when hormones promoting alertness are at their highest levels.

And that's exactly the time I tend to sit down

to do what I call a bit of work.

I'm a one-finger man, so it does take a little bit of time,

but then I have plenty of time.

But some people need to be at their peak of alertness

at all times of the day and the night.

Nearly four million people in the UK work shifts.

So, how do they concentrate when their shift patterns demand

they override their body clocks?

This is the early shift at Turners Distribution Centre in Newmarket.

While most of us are sleeping,

they're at work to make sure our fresh groceries

are there when the shops open.

We asked the workers here if they thought they were a lark or an owl.

Remember, that's the time they like to get up,

not the time they have to get up.

So that's 12 larks and only five owls.

Now, this is to be expected, really.

Most owls who try to do the early shift

will give up after just a few weeks,

leaving larks in the majority.

So, what's it like being an owl on an early shift?

I just cannot do mornings. I hate mornings with a passion.

Very, very grumpy and generally don't like to talk to people much.

I've always stayed up late. Very difficult to get up.

Always late for work. Every morning, I think, I'm late.

Shift work is the ultimate clash

between the time our body clock wants us to do things

and the time modern life demands we do them.

And it shows.

People who do night shifts for many years have a much higher risk

of developing life-threatening conditions.

24-hour living comes at a cost.

ALARM

The middle of the day or the early afternoon

is when we feel at our most positive.

That's the time you should be asking for a raise.

And it's the best time of the day to go to the dentist

because the local anaesthetic can last up to three times longer.

But I'm afraid it's the worst time of the day

to have an alcoholic drink.

If I have alcohol at lunchtime,

I can't have more than one, because I'd be zonked out.

If I had a drink earlier in the day, I'd feel more tired after,

but if I had a drink later in the day, then I'd be more energetic.

If I daytime drink and I stop,

I fall asleep at 5:00 and sleep heavily.

I'll just go to bed.

I like to have a small bottle of lager with my lunch,

but I know it afterwards.

Yeah, it definitely makes me tired.

So, why does drinking during the day

have much more effect than drinking in the evening?

Surely it can't be influenced by the body clock, as well?

It's a warm day here in London.

And in the name of science, we're going to crack out the wine.

We've enrolled two sets of volunteers.

One lot, who will join us later on,

and this group, looking forward to a tipple at lunchtime.

Each of them gets one roll and two and a half units of alcohol.

Or as I like to call it, hardly anything to drink.

-Grab a roll, for goodness' sake.

-Ooh, yes.

-Have you got enough wine?

-I-I think so.

Because this experiment only works if you're drunk. Drink up.

-Will do.

-Drink up.

In the early afternoon, our body clock

tries to tell us to have a little nap.

And somewhat surprisingly, it seems to do this

partly by dipping our body temperature.

Only by a tiny amount, but it's enough

to cause slight drowsiness in most of us.

In the mid-afternoon,

we're starting to get sleepy.

This is when, if we lived in Spain or Italy or somewhere,

we might be thinking about having a siesta.

So we have this effect of sleepiness and alcohol combined.

So our lunchtime lab rats have had a drink

at a time when their bodies are telling them to fall asleep.

How will they cope with a simple task of concentration?

Three, two, one, go.

And the aim of the test is to sort a pack of cards into suits

and then numerical order.

We're looking at how fast they can do it,

but more importantly, how accurate they are.

Oh, no!

And some of the group are finding the task quite confusing.

I think two comes before three and then four, then five, six, seven.

You're probably right.

Do you think it's the drink, or are you just not very good at cards?

I'm not very good at cards and I don't normally drink at lunchtime.

It's quite challenging, to be honest. It's harder than you think.

My brain is not all the way on.

I'm feeling a little bit woozy from the wine.

So they're not coping well.

How will they compare to our second group,

who do the test in the early evening?

I've found my vocation at last. Pouring drinks.

If you eat a sandwich, as well.

Thank you very much. Cheers!

Ready, steady, go!

By this time, our bodies should be recovering from their lunchtime dip.

And don't panic.

So in theory, this group should cope with the alcohol better.

It's interesting because this group now, this evening,

are using more strategy-based techniques for sorting out the cards,

whereas this afternoon, people were just kind of going for it.

Whereas now, they're using strategies.

Their brains are working in a different way.

She had an interesting tactic because she was sorting by suit

at the same time by number.

So I think it worked well for her.

Yeah, I think I did all right.

I was trying to get the cards out as quick as possible.

So, Louise, tell me all. Spare me nothing.

OK. When we look at the time taken to do the task,

people did take very slightly longer to do the task this evening.

However, during the evening sessions, accuracy was much improved

and their brains were perhaps working a little bit better

for them to be able to do that task more accurately at this time of day.

In fact, larger studies have shown

that many aspects of brain function and alertness

suffer a dip during the afternoon.

And where does this come in? How is this useful to anybody?

Well, and this is important, for something like driving, for example,

where you might take perhaps a small measure of alcohol

and it would have a much stronger effect on you

in the daytime than at night-time.

So although this group may be a little slow,

they are, in fact, more accurate.

More accurate, yes.

CHEERING

This natural slump caused by our body clock

means drinking during the day, even under the legal limit,

will have a much bigger effect on our ability to concentrate,

regardless of what we're doing.

You know, more people die on British roads between 1:00 and 5:00pm

than at any other time of the day.

And now I understand why.

Our European cousins have the right idea.

The best thing to do in the afternoon

is definitely enjoy a siesta.

ALARM

# Bung, bung, bung, bung, bung

# Bung, bung, bung, bung, bung

# Mr Sandman, bring me a dream...#

So it's bedtime.

And in my case, that's 11:30.

Now, when I was getting up at the crack of dawn

to do the morning radio show,

I would go to bed around about 10:30.

Now, that, I understand, is the average bedtime

for most British people.

But I suppose since I have a bit more time on my hands,

I come to bed an hour later.

But once a year, I bravely override my body clock

and stay up and active much later

presenting the show closest to my heart, Children in Need.

Rehearsals start in the afternoon, but the live show lasts

until the early hours of the next day.

# Let's go crazy, crazy, crazy

# Till we see the sun...

Thank you for joining us.

# I know we only met but let's pretend it's love

# And never, never, never stop for anyone

# Tonight, let's get some and live while we're young. #

Well, that's it. 2:10 in the morning.

Probably won't wake until,

oh, maybe 10:00 tomorrow morning, who knows?

This morning. What am I saying?

The adrenaline kept me going.

I'm not sure I could do it too often.

However, there is one group of people

who like to stay up this late every single night of the week. Teenagers.

We all know teenagers have a reputation for being a bit lazy,

but it turns out there may actually be

a biological reason for their behaviour.

When we swot analysis, what would an example of a level one question be?

Marketing, planning.

These young people need a whopping nine hours' sleep,

so to be fresh and ready for lessons that start at 9:00 in the morning,

they should be going to bed by 10:00 or 11:00 in the evening.

Now, I know, as someone with three grown-up children,

this is highly unlikely.

It's a planning tool. What does it help us do?

-Excuse me.

-Hi, there.

Sorry to interrupt the class. Good morning, everybody.

-ALL: Hello.

-Morning, teacher.

-Good morning.

Could I ask you all to stand, please? Thank you.

This is an experiment.

So could I ask those who go to bed or sleep at 11:00 to sit down.

That's encouraging.

Could I ask those who go to sleep at midnight to sit down.

You see, that's me. And you need so much more sleep than I do.

What about those who go to sleep at 12:30?

And you, what time do you go to sleep?

-About 1:00ish.

-Do you?

-Yeah.

Sit down, for goodness' sakes.

Look, there's four girls standing. Are you ravers?

LAUGHTER

Are you all clubbing at all hours?

What about your studies?

-Do you not feel cream-crackered in the morning?

-Yes.

1:30. Is that when you go to sleep?

-Yeah.

-1:30-2:00ish.

-Sit down, for goodness' sake.

Frightening.

A preference for very late nights is all to do with puberty.

From the ages of around 14 to 20,

the body clock shifts and we become super owls.

We don't really know for sure why it happens,

but it's a measureable biological change.

And it means being alert for early lessons can be extremely difficult.

Instead of asking teenagers to force their body clocks to change,

some schools are looking at the problem the other way around.

The interesting thing about this school

is that the older students come in at 11:30,

which is about the right time for teenagers and adolescents

to actually be in school.

They should wake up about 10:00

and they should start work, you know, at 11:30.

You will get people like myself who are very intolerant of this kind of thing

saying, "I had to get up at all hours,

"I had to work hard, discipline and duty and all the rest of it

"and now we're catering for the little rascals."

I think we're not catering for the little rascals

because, in fact, what we're saying is it's not for them,

it's for their health and their sleep.

So, if you like, it's a different kind of medicine.

It's just a kind of medicine that they like

because it actually makes them feel better.

I mean, to put it another way, if you, as an adult,

had to get up at 3:30 in the morning to go to work,

you'd be experiencing what teenagers experience with early school start.

So, what are the results?

Will these young people have better exam results?

In every study everywhere in the world,

later start times produce better results.

And, according to parents and teachers, better young people

in terms of their behaviour

and their mood and their attitude to things.

These pupils, they work really hard.

They work an awful lot harder on their exams than I did

and they all seemed balanced, happy and healthy,

which I think is probably the object of the exercise.

I'm terribly impressed with this.

The fact that the body clock idea has been put to practical use.

It's been put to benefit the next generation,

which is probably the most important thing you can do.

ALARM

Of course, with our busy lives,

we can't always do things as and when our body clock dictates,

but maybe we should make an effort to try and do them at the right time

a little more often.

Trust me, you'll be glad you did.