Eight Horsham students have taken part in the gruelling 14km the Warrior Run raising hundreds of pounds for Help For Heroes.
The pupils of the College of Richard Collyer were among the youngest taking part but managed to complete the course in two hours, 11 minutes - half an hour short of the average.
They ran twice around a 7km course facing challenges including a deep muddy water ravine a 12ft high wall and a 20ft abseil. Elements such as a giant water slide into muddy water and monkey bars made from tractor tyres proved to be good fun for the teens.
Luke Saunders, 16, said: “The Warrior Run was an amazing experience but was so much more physically demanding than I expected, especially the second time round.”
They were helped by knowing why they were doing it.
Alex Clery, 17, said: “It was a really difficult course but it was also so rewarding at the end because we knew that it was for a good cause.
Rory Slatter, also 17, added: “It was a very tough course but we all got through it eventually, and we were glad to be able to make a difference through contributing to such a good cause.”
So far the team have raised £1,300 with donations still coming in. To donate visit www.justgiving.com/hyow