MORE than 20,000 people will take part in an endurance event in Henley this weekend.
Tough Mudder features a 12-mile obstacle course for teams that is designed to test physical and mental strength but which puts camaraderie above competition.
It started in America in 2010 and now features more than 50 events worldwide.
The London West event will take place for the second year running at the Culden Faw estate, near Fawley, on Saturday and Sunday and thousands of people are expected to watch the action.
Organisers say the landscape and the proximity to London have made it one of the most popular events on their calendar. Marketing director John Fidoe said: ?Henley was a new event last year and went fantastically well. We had a huge response and people loved the venue so we were keen to come back. The venue is great as there are lots of ups and downs and the course has great variety.
?We look to be close to big cities because we don?t want people to have to travel far and Henley is ideal for people from London as well as Reading, Marlow and High Wycombe.
?The town itself has such a beautiful setting and people want to visit and make a weekend of it.?
Tough Mudder is known for its challenges, including having to crawl through a pit with live electrical wires, leap into icy water and climb a 15ft slippery ramp nicknamed Everest.
Mr Fidoe said: ?We have made some changes this year and Henley is the first chance our UK Mudders will get to see those.
?Tough Mudder is different to a marathon as it?s not just trudging along a 26-mile course.
?You test yourself in different ways and often it?s about getting round as part of a team. In fact, 95 per cent of people who take part in Tough Mudder do it as a team and our biggest group was 500 at an event in Ireland.?
Residents are warned to avoid the A4155 between Henley and Marlow on Saturday morning, when traffic will be at its busiest.
Mr Fidoe said: ?Obviously we try to minimise disruption as much as we can but the event is so popular that there will be a lot of congestion on Saturday morning. We?ve done all we can to keep the disruption as low as possible.?
Alex Dick, estate manager at Culden Faw, said: ?We went into Tough Mudder with open eyes, conscious that it?s a large event and that it could cause disruption.
?The benefit is that it?s all within the estate so it doesn?t cause road closures and they have a very good traffic control system.?
Mr Dick, who took part last year, added: ?It?s a fantastic event and this is the most popular one in this country.?
Among those taking part this year will be Miss England hopeful Hannah Baker, 22, of Rotherfield Road, Henley. She and a friend will be raising money for children?s charity Beauty With a Purpose.