Would you take part in a race with no finish line?

Whether at sports day, an athletics club or simply a quick race against your mates or siblings, there's plenty to love about running.

But how would you feel about a race with no set finish line?

Well such a race does exist, it's called a backyard ultra and teams have been battling it out to be crowned world champions.

But if there is no finish line, how do you know when you've finished?

Well, as an endurance race, the last competitor or team still going, wins.

Once the race starts, you have an hour to run 4.167 miles (6.7km).

Some of you might think that's not too bad, but the challenge is that runners have the remainder of that hour to rest, before going again - and this continues until competitors can't run any further.

On Saturday October 17, 990 runners from 67 nations set off in the Backyard Ultra World Team Championship.

The competition runs for days and days, until only one person is left running.

The team championship works slightly differently with the total number of laps - known as yards - being added together, and extra points are awarded to teams with individual runners who manage more than 30 laps.

If you are trying to work out the kind of person that would attempt this incredible feat, perhaps you could look towards your teacher.

The world record for the women's race is held by Sarah Perry, a teacher from Cockermouth, she managed a whopping 95 laps.

It took the teacher four days to complete the amazing distance.