Real British English : Larks and owls

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. 
 
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.  
 
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 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 home-lighting 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:
 
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!