Mathew Sirett, 29, will tackle the Tough Mudder North West, alongside his friend Jake Lane, 27, from Alford, on September 9.
Mathew’s grandfather, John O’Hanlon, from South Reston, was supported by the Louth branch of SSAFA, the Armed Forces charity, as his health deteriorated over the last few years.
SSAFA provided John, who served in the Navy, with an electric reclining chair, a disability car, and much more in his final years.
Even after he passed away in February, SSAFA continued to support his family, such as helping his widow Vera with funeral costs and filling in the necessary paperwork.
Mathew said: “Without the help of Iris Dainton, from SSAFA, I don’t know how my grandparents would have managed.
“Because of this, myself and my good friend Jake (who is in the Army) have decided to complete the Tough Mudder course. Our aim is to raise awareness and money for this amazing charity.
“We know this event is going to test our mental and physical capabilities. Anything you can spare to donate is much appreciated.
“We will keep everyone posted with our training and story along the way! On behalf of myself and Jake, thank you so much in advance to everyone who donates.”
Iris Dainton, SSAFA’s Louth Divisional Secretary, told the Leader: “I am extremely grateful to Matt and Jake for volunteering to raise money for SSAFA.
“As the Armed Forces charity, SSAFA is dependant for support from donations by the public.
“All of its caseworkers are volunteers, as I am, with a remit to try to help any ex-servicemen and women we come across, who are in need of assistance.
“I know that Mathew was particularly glad of the help I was able to give to his grandfather and grandmother at South Reston.
“In return he and his friend have undertaken this challenge in a bid to raise money for SSAFA Louth, to thank us for our support.
“Now it is only a few weeks away, I hope others will be inspired to help and show support for these two (and for SSAFA) by donating as much, or as little, as they can.”
• Visit www.justgiving.com/fundraising/Matt-Jake-ToughMudder2017 to find out more and make a donation.