Stephen Ready, Andy Howell, Patrick Mackie and Daniel Healey face the daunting prospect of an assault course designed by Special Forces for the ultimate test of strength and endurance.
The 12-mile run, which raises money for Help for Heroes, includes between 20 and 25 obstacles with names like Electric Shock Therapy, Boa Constrictor, Mud Mile and Fire Walker.
In preparation for the challenge on Saturday May 4^th, Mr Ready, Mr Howell and Mr Mackie joined geography teacher Matt Fowler for the recent Farmageddon run at Melton Mowbray. The 10k off-road obstacle race included hay bale jumps, carrying logs up steep inclines and swamp wading.
Mr Fowler was the first runner out of around 300 to finish, taking 54 minutes and four seconds to complete the course - a full five minutes before the second runner came through. He is unable to take part in Tough Mudder because he had already signed up to the Milton Keynes marathon which is on the same day.

While the group has some experience of extreme assault courses, they admit they are a bit apprehensive about Tough Mudder, which attracts competitors from around the world who are looking for the ultimate challenge.

Mr Howell said: "I'd say we're excited but with a large degree of nerves."

The group will be setting up a sponsorship page - more details available soon.