Two men from South Cumbria are preparing to swim, run and cycle the three classic Lakeland endurance rounds back-to-back.
Kirk Wadsworth and Tim Jenner are hoping to do the Frog Graham Round, the Bob Graham Round and the Fred Whitton Challenge, completing all three in less than 60 hours.
Nobody has been known to complete all three feats consecutively.Mr Wadsworth, 47, and Mr Jenner, 45, have both been juggling family life, jobs and training for the last year.
It has all been about 'The Cumbrian' extreme endurance challenge.
Facts about The Cumbrian:
The Bob Graham Round: running 106km over 42 peaks, in 24 hours
The Frog Graham Round: swim four lakes in a 40-mile fell run
The Fred Whitton Challenge: 180km over all the Lake District mountain passes
Mr Jenner told ITV News Border: "I'm very excited about it but extremely nervous because a lot of people are counting on us getting around, they've pledged lots of money.
"I've put a lot of people that are close to me through a lot. My poor wife's had to put up with me getting up at 4am, being miserable, going through those emotions.
"I've got two children, I guess I've been away from them more than I should be because I've been training."
The pair hope to raise £10,000 for three local charities Jigsaw, the Brathay Trust and Keswick Mountain Rescue Team.
Mr Jenner said: "Jigsaw is a children's hospice, and the sort of work I do is working with children with severe learning difficulties so it resonates very well with myself and hopefully lots of other people."
The Brathay Trust's aims include getting young people into the outdoors, which Mr Wadsworth said is often taken for granted.
As for Keswick Mountain Rescue team, the pair are hoping they will not need to call for their help - but want to give something back to the team that go to people's aid all year round.
During the challenge Mr Wadsworth and Mr Jenner will journey over 350km, traversing 17,000 metres of elevation in 60 hours.
Their three-hour rests between the rounds include time for showering and eating. Sleep deprivation, however, will be one of their biggest challenges.Mr Wadsworth said: "We know that we're going to go to some dark places. It's as much a mental challenge as it is a physical one.
"We're stepping into the unknown a little but that's part of the appeal."An added hurdle to the challenge is that it will still be the end of the heatwave when they begin on Friday 22 July.
Many of the small freshwater tarns and streams in the mountains which the pair were relying on for during their challenge have started to dry up - meaning they will need to carry lots of extra water.