Some 15,000 people took part in a muddy challenge in Arnsberg, Germany, on Saturday.
Competitors had to overcome more than 20 obstacles through sludge and muddy waters.
The 'Tough Mudder' obstacle race originated in the US state of Pennsylvania. The first such race was held there in 2010.
The punishing mud-fest has found a worldwide fan base. In Germany alone, there are three such mud races this year alone.
But according to the organisers, the course in Arnsberg is the toughest mud obstacle course in Europe, with the highest incline.