David Timmins, 32, took the full force of a blast while on bomb disposal duty for the Army in Afghanistan. He suffered 22 separate injuries and spent more than 18 months in hospital.
But now he is part of a team attempting to cover 500 miles across a series of sporting challenges.
And all the money they raise will go to Glasgow's Helping Heroes, which is based in Duke Street, where David works.
The organisation provides support and advice to servicemen and women making the transition back into civilian life.
And as part of the challenge, David, from Barrhead, Barry Henderson, his boss at the charity, and a team from Renfrewshire Leisure, where David's wife Liz works, are taking on the infamous Tough Mudder Challenge today and tomorrow at Dalkeith County Estate, West Lothian.
It is a gruelling 12-mile assault course. Among the 20 obstacles they have to negotiate, participants must jump into a dumpster of ice; sprint through a field of live wires carrying 10,000 volts of electric shock; make their way around a military course that requires crawling through narrow, dark, muddy, trenches; and scaling 12ft walls.
The average time to complete the course is 3½ hours.
David, who admits training is hard as he runs "awkwardly" as a result of his injuries, says he is delighted to help other servicemen and women.
He said: "A lot of the guys who come to us for help feel they can talk to me. I have been to the same places they have.
"Anybody that has served, I believe they should get the care. They are doing a job not a lot of people would do. They are dedicated to what they do.
"And with the redundancies and cutbacks in the Armed Services, a lot of people are leaving when they didn't want to leave and finding themselves unemployed and homeless. That's were we come in.
"The money we raise will go to predominantly Glasgow veterans through Glasgow's Helping Heroes. We have an emergency fund. We often get guys who find themselves in hard times, and can't even feed themselves. We can help.
"We also provide grants for training and rehabilitation."
Taking on the challenge will mark another milestone on the long road of recovery that David has been on since the blast which he describes as "a bit of a show stopper".
He said: "We were on a routine route clearance in 2009 during operation Panther's Claw in Afghanistan. Unfortunately, we missed a device, a booby trap in a wall.
"That was the deal. It was a show stopper. I remember nothing. I woke up 12 days later in hospital in Birmingham.
"I had 22 separate injuries: a fractured skull, cheek bone shattered, my jaw was shattered, broken neck and back, liver and kidney damage, I was paralysed down my left side, lost an eye, partially deaf in one ear. I'm lucky to be alive."
Glasgow's Helping Heroes fundraising campaign for 2013 is to cover 500 miles by walking, jogging, running, cycling, and climbing in a number of events in the city and further afield.
More than 50 people will be involved and team members include a wide range of people, from Armed Services' veterans to grannies, partners, children and even dogs of veterans.
The team have support from a range of organisations, including Glasgow City Council, Renfrewshire Leisure, Glasgow Housing Association, Gailforce Services and others.
Derek Cuthbertson, manager at the Lagoon Leisure Centre, Paisley, which is run by Renfrewshire Leisure, said: "When we heard about the plan we thought, 'Good challenge and a good cause'. We have a team of 16 taking part. It's going to be tough.
"Renfrewshire Leisure agreed to cover half our entry fee and Anytime Leisure are sponsoring us up to the same value, which means any money we raise will go straight to the charity."
To find out more about Glasgow's Helping Heroes see: www.sites.google.com/site/ glasgowshelpingheroes/home