Oliver McKenna wins the World Mountain Bike Bog Snorkelling Championships in Wales on Saturday (27th August).

If you're sad about Rio being over, don't worry: the organisers of the World Alternative Games think they've got just the event to fill the gap.

We're at the peat bog in the small village in Wales that hosts the Mountain Bike Bog Snorkelling Championships.

It's possible you haven't come across mountain bike bog snorkelling before, so just in case, here's the lowdown. Competitors ride a mountain bike along the bottom of a two-metre-deep water-filled trench for 45 yards, wearing a snorkel so they can breathe when fully submerged.

Floatation is a common issue when bike bog snorkelling, so the bikes are specially prepared with a lead-filled frame to keep them in the trench, and the riders wear lead weight belts.

Tyres are filled with water beforehand so you can grip on the bottom of the trench, and you'll be glad to learn that these divers are on hand for safety purposes.

Here's this year's world champion Oliver McKenna, a 36-year-old mountain biker from Brighton in the UK.