World's Biggest Triathlon

7 August 2010, 05:54

More than 10-thousand people will take part in the world's biggest triathlon in London this weekend.

Formula 1 World Champion Jenson Button's thought to be taking part at the event at the Excel Centre in Docklands.

It's the 14th time we've held the event here.

Around 55 thousand people are going to go along to watch.