James Blackmore, from Chirk Bank, will be doing the Dave Goggins Challenge, created by the American ultra-marathon runner, at the end of March.
It means he will be running four miles, every four hours for 48 hours – all in aid of Hope House Children's Hospice.
“It’s both a physical and mental challenge of endurance,” said 30-year-old James, who is a self-confessed rookie runner.
“I’ve been training for a while, but I didn’t realise quite how tough it was. In September I hit it too hard and got tendonitis, so had to have six weeks off.
“But I’ve been training better since and am hopefully going to be well prepared.”
James, who has family that have used Hope House’s services, has said having his wife Sian and two young boys Arthur and Walter cheering him on has spurred him through the training.
“Hope House is a great local charity and their support is vital to those that need them,” said James, who works at Arla Foods in Oswestry.
“I can’t think of a better place to fundraise for and knowing where the money will be going will spur me on to complete the challenge.”
The pandemic has been a challenge for Hope House Children’s Hospices, which has faced a loss of income of £1.25 million.
Cat Dowdeswell, fundraiser, said: “It is people like James, and all of those who have been fundraising for us over the last year, which have meant that we are still able to be here for seriously ill children and their families.
“We wish James the very best of luck, this is going to be quite the challenge.”
Anyone who would like to support James can do so at justgiving.com/fundraising/James-Blackmore10.
People who want to raise money for Hope House can also enter the Take A Hike! event on March 28, where hundreds will be pulling on their walking shoes and walking a 10-mile route virtually.
People can sign up at hopehouse.org.uk/hike.