Today, a big health warning for 1.8 billion people around the world who don't do enough exercise.

Hello, I'm Neil.

And I'm Georgie.

In this programme, we look at one big news story and the vocabulary in the headlines that will help you understand it.

You can find all the vocabulary and headlines from this episode, as well as a worksheet, on our website bbclearningenglish.com.

So Georgie, let's talk a little bit more about today's story.

A World Health Organisation study, that's WHO, has found that around 1.8 billion people in the world are inactive.

That means they do not move around enough.

Yes, so according to the WHO, adults need to spend at least 150 minutes a week doing moderate activity or 75 minutes a week doing vigorous – that means energetic – activity to stay healthy.

The results are part of a worldwide study and show that more people are inactive globally than the last study in 2010.

So our first headline describes the results of the report.

It is from Medical Express:

'Wake-up call': third of adults not doing enough physical activity

OK, let's hear that again.

'Wake-up call': third of adults not doing enough physical activity

And that's from Medical Express.

We're going to start by looking at the expression right at the beginning of that headline: wake-up call.

Yes, and we know wake up as a phrasal verb, it means to stop sleeping.

So you're in bed, you're sleeping and in the morning, we wake up.

But Neil, what about wake-up call as a noun?

Well, yes, let's think of a wake-up call like an alarm.

So it's something which forces you to stop sleeping.

Literally, you can get a wake-up call in a hotel where you ask them to call you at a certain time in the morning to wake you up.

Yes, but in the headline, wake-up call is more metaphorical.

So we're not talking about the literal sense like a hotel wake-up call.

It's like a warning or reminder that we need to wake up and do something about this problem, according to this WHO study.

So Neil, in what situations can we use it?

Well, it's used a lot in situations where we suddenly get information which reveals a serious problem and suggests that we need to change.

So, for example, it was my dad's birthday recently and I wanted to buy him a nice present.

But I realised I'd spent all of my money so I couldn't really afford to buy him what I wanted to and that was a wake-up call for me to organise my finances better.

That was wake-up call, a piece of information which gives a strong warning about a problem.

For example, this practice exam was a real wake-up call.

I really need to study more if I'm going to pass the real one.

This is Learning English from the News, our podcast about the news headlines.

Today, we're talking about a WHO report which says 1.8 billion people across the world are inactive.

So, as we've heard, the results of the study show that more people in the world are not doing enough exercise or moving around enough.

So what's the problem?

Well, the reason the WHO are concerned about this is because scientists have linked inactivity to lots of serious health problems.

Yes, for example, inactivity is thought to increase the risk of strokes, heart attacks, diabetes and some cancers.

And we actually have a headline here which talks about these risks.

It's from The Sun and it says, "Laziness is 'silent threat' putting 1.8billion at risk of heart attacks, cancer & dementia, WHO warns."

So let's repeat that headline.

Laziness is 'silent threat' putting 1.8billion at risk of heart attacks, cancer & dementia, WHO warns.

That's from The Sun.

So that headline starts with the word "laziness"which the writer has used to describe people who don't do enough activity.

Of course, it's more complicated than that.

There are some people who can't do things, not because they're lazy, because they're not able to move.

Yes, and we are interested in this expression, "silent threat", which is how the WHO described high levels of inactivity.

Neil, how can a threat be silent?

Well, we use this phrase to talk about threats or dangers which people don't know about or they can't see.

Yes, in this story, silent threat is used to show that people don't realise that inactivity increases their risk of lots of diseases.

And Georgie, we hear also a related expression, "silent killer."

Silent killer, to talk about a serious disease which has no obvious symptoms.

Yeah, it's quite a dramatic term, often used to draw attention to something dangerous, as with silent threat in this headline.

Yes, and a good example, I think, of a silent killer is high blood pressure because lots of people have it and they don't realise that it can be really bad for you.

We've had silent threat, a danger people don't know about or can't see.

For example, this email system is a silent threat to the company.

It could be hacked really easily.

This is Learning English from the News from BBC Learning English.

We're talking about a report showing a third of the world's adults are inactive.

Yes, and beyond the headline number that 1.8 billion people globally are inactive, the results show what the situation is in different countries around the world.

Yes, and the highest levels of inactivity were found in South Asia and a region called high-income Asia-Pacific countries, for example, Japan and Singapore and South Korea.

And the results also show that more women were inactive than men.

Let's have another headline, this one from The Telegraph:

Britons are inactive – but WHO figures reveal they have leapfrogged one rival

Let's hear that again.

So this one's from The Telegraph: Britons are inactive – but WHO figures reveal they have leapfrogged one rival

OK, so this headline is looking in detail at how different countries performed in the survey, particularly Britain.

And it mentions a rival.

Georgie, any ideas who that rival could be?

I'm thinking European, I'll guess France.

Well, we'll find out later.

OK, but we're looking at this word "leapfrogged," which is quite a funny word.

What have frogs got to do with anything, Neil?

Well, it's not really about frogs, it's about a children's game.

And you probably know this game and it probably has a different name in your country.

But Georgie, you know that game when somebody bends down and another person jumps over their back.

That, as a verb, is to leapfrog.

Oh yes, actually I remember playing that game at school.

But this headline isn't literally about the game, is it?

No, we're talking about leapfrogging metaphorically.

So in the headline, if Britain leapfrogged their rival, it means they jump over the top of them and ahead of them in the results.

So basically, last time Britain did worse than their rival, so they were more inactive than their rival.

This time they did better, so they were less inactive.

They've leapfrogged them.

So Neil, who is this rival?

It's actually Australia.

Britain and Australia have a friendly rivalry and this is really a kind of fun article.

It's not really a competition between countries, but the writers are pointing out something interesting from these results.

OK, so back to leapfrog.

We can use this in sports or other competitive situations to describe that specific situation of jumping ahead of someone.

We had "leapfrog" - jump ahead of somebody in a competition.

For example, my favourite football team has been leapfrogged in the tournament by their rivals.

This is a nightmare!

That's it for this episode of Learning English from the News.

We'll be back next week for another news story.

If you've enjoyed this programme, we explore lots of stories about health in 6 Minute English.

You can listen on our website bbclearningenglish.com.

And don't forget to check out our social media channels, look for BBC Learning English.

Bye for now.

Bye.