6 Minute English © bbclearningenglish.com 2010
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Dan: Hello and welcome to this week’s 6 minute English. I’m Dan Walker Smith
and today I’m joined by Kate.
Now Kate, would you say you’re more of a morning or an evening person?
Kate: I’d say I’m definitely a morning person. I love going to bed early and getting
up early.
Dan: OK, well that makes you a lark. People who are better in the morning are
known as ‘larks’, after the famously early-rising birds. And people who are
better at night are sometimes known as ‘owls’ or 'night-owls', after the birds
which tend to come out at night.
Kate: That’s an interesting theory. How about you? Are you a morning or a night
person?
Dan: I’m definitely an owl. I go to bed very late and I love staying in late in the
morning. I just don’t deal with daytime at all.
Kate: Oh, so we’re complete opposites then.
Dan: Yup.
Kate: Well, apparently around half the world’s population are naturally co-ordinated
to wake up early or late. It’s in our genetics or make-up, like our eye-colour or
height.
6 Minute English © bbclearningenglish.com 2010
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Dan: So this week’s question to you Kate is: on average how many hours do adults
sleep each night? Is it:
a) 6 and a half hours
b) 7 and a half hours
c) 8 and a half hours
Kate: Well I think that the recommended amount of sleep is somewhere between
seven and eight hours. But I’m sure that most people don’t get that amount, so
I’m going to go for a, six and a half.
Dan: OK, we'll see if you're right at the end of the programme.
Kate: Now, a person's natural rhythm of sleep is known as their body clock. This is
what regulates what time you wake up and when you feel tired. Variations in
your body's temperature affect tiredness, so some people are naturally more
alert or awake during the morning hours, and others are more productive late at
night.
Dan: Before we had electricity, our sleeping patterns were basically decided by the
sun. We would get up at dawn, when the sun rises, and fall asleep at dusk,
when the sun goes down.
Kate: But now unfortunately the pressures of work and society mean that most of us
don't follow our natural body clocks or the rhythm of the sun, so we often don't
get enough sleep.
Dan: Now we're going to hear now from sleep specialist Professor Till Roenneberg
on how modern working life is affecting our sleep patterns. You'll hear the
word optimally, which means 'in the best way' and also the words internal
and external.
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Kate: Internal means located inside, and external refers to anything happening on
the outside – in this case inside or outside the human body.
So have a listen. How are people who naturally stay up late affected by modern
working hours?
Extract 1
We have to be aware of the fact that the very late people are actually on a permanent
shift working schedule, because they have to get up against their body clock and they
don’t perform optimally, and so forth, very often they don’t get enough sleep.
Because what’s happening is that the signal that allows people to fall asleep comes from
the internal body clock, whereas the signal on work days to get up comes from an
external clock.
Dan: OK, so owls - people who naturally wake up late and stay up late – can often
feel tired because they're working against their body clock. They don’t perform
optimally because they haven't had enough sleep.
Some people compare the experience to jet lag – what do they mean by that
Kate?
Kate: Well jet lag is the tiredness you feel after you've been on a flight and have
travelled to a different time zone. So when Professor Roenneberg here calls the
experience of living on a different cycle to your work companions a 'social jet
lag', he means it causes the same sort of tiredness that you get after a long
flight.
Extract 2
If you fly from New York to London, you are in a completely new light/dark cycle;
you’re flying somewhere else. And that earlier sunrise will make your clock adapt to
exactly the London time. But with a social jet lag, it’s your internal and external times
6 Minute English © bbclearningenglish.com 2010
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that are out of sync, and nothing in the conditions of light or darkness will change. And
therefore you will stay like this all your life.
Kate: It sounds miserable; you're essentially not co-ordinated – or out of sync – with
the time zone you're in, so you're tired all the time. Sync is short for
synchronised, which means to happen at the same rate or speed. So if
something's out of sync, it's happening at the wrong pace.
Dan: We also heard the words internal and external again, this time referring to
time-zones.
Now the best way to adapt your body clock to a new routine is with light. If
you're not great in the mornings, try to get out into the sunlight as soon as
possible. And if you get tired in the evenings, you should try to spend some
time outdoors then.
Kate: So here's the British sleep scientist Russell Foster talking about the affect of
light on our body clock. Can you tell me how much brighter sunlight is than
artificial light?
Extract 3
If we look at the average amount of light in the home environment or the office
environment, it’s extremely low. So, for example, shortly after dawn, natural sunlight,
even in the UK, is some 50 to 100 times brighter than average office-lighting or homelighting
conditions. And by noon natural light is some 500 to 1,000 times brighter.
Kate: So it would take an awful lot of artificial light to adjust your body clock in the
same way sun can.
Dan: OK we’re almost out of time, so let’s go over some of the vocabulary we’ve
come across today:
6 Minute English © bbclearningenglish.com 2010
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owl and lark
body clock
dawn and dusk
internal and external
jet lag
synchronise
out of sync
Dan: And finally Kate, back to today's question: I asked you how much sleep adults
get to sleep each night?
Kate: And I went for a, six and half hours, because I’m sure people don’t get enough
sleep these days.
Dan: Well I read that apparently it’s seven and a half hours. But I certainly don’t get
that and don’t think most people do either.
Kate: Interesting. Well I aim for about ten, but I rarely get that either.
Dan: Well, from all of us here at BBC Learning English, thanks for listening, sleep
well, and goodbye!
Kate: Goodbye!
