When we think of endurance sports, we might think of Ultramarathons or Ironman triathlons.

But there's a new discipline in Sweden that's gaining a reputation as one of the toughest in the world.

It's called swimrun. Team of two swim and run a total of 75km among and over 26 islands in Stockholm's archipelago.

It's now in its 10th year and gaining popularity.

Paul Rhys explains.

Source: Al Jazeera