In 2010, Private Steven Richardson stepped on an improvised explosive device while serving in Afghanistan.

"Two weeks before getting blown up, I had found four in the area," he says.

He found his fifth by standing on it.

"Still counts," he says with a laugh, "I found it." The explosion, though, nearly cost him his life.

The blast was so powerful, it instantly amputated both his legs and blew the two soldiers beside him off their feet.

They were on him in seconds. Tourniquets were tightened to try and stop the blood flow, and morphine was flooded through his system to dull the pain.

A Chinook flew him straight to Camp Bastion where litres of blood were pumped into him before he was flown out to Birmingham.

He was unconscious for four days as paramedics battled to save him.

But Steven had decided he wasn't going anywhere. He was 22-years-old and a stubborn streak as hard as metal was forming.

He opened his eyes and looked around clearly, to the relief of his doctors who had feared dust from the blast had blinded him.

Five weeks later he was home, back to the 1 SCOTS Dreghorn Barracks in Edinburgh and to his partner, Laura.

This time he was in a bungalow, better suited to his new wheelchair.

He had no intention of staying in it long.

Six years and countless physiotherapy sessions later, Steven sat typing out an email that was to change his life.

He didn't know it yet, but the man he was sending it too was about to catapult him on a mission to become one of the strongest men in the world.

"I must have written the email three or four times before I sent it," says Steven. "I thought a lot of people would see it and think insurance nightmare."

It had been a glance that had done it. A sign by the side of the road he had spotted by chance on a drive down to North Berwick.

It was for an event called 'Strongman'. On the drive back, Steven made sure to note down the details. He looked up the group and finally sent off the email he'd struggled to find the words to write.

He'd tried to do things like this before, but had always run into the same tough wall. People were too nervous to train him, unsure of his disability and of what he could do.

"I'm an ex-soldier," he wrote. "A double amputee". He clicked send.

The reply was immediate. Kenneth Simm, an ex-Royal Marine Commando, hadn't hesitated.

There is a traditional boisterous rivalry between marine and army soldiers. When it came right down to it though, Kenneth saw Steven, a man who had been a soldier just like him, who had risked everything to protect the same things he did.

He was a brother in arms and he needed Kenneth's help.

"We had this connection straight away I guess," says Kenneth. "He hadn't realised I was ex-military and I think it helped."

It was a moment they both remember. The pair met, and since that day, Steven has continued to train with Kenneth by this side.

"To be honest, when I first met him, I had to think of things he could actually do as he only has five fingers in total and grip is a bit of an issue," says Kenneth.

"He has two different legs he uses and it was a bit of a shock when I first saw him. I tried him on everything and it took a month to work things out."

But the pair did it. Steven's high intensity workouts had begun, and with them came a new focus, partly due to the very persistent marine.

"I convinced him to try out for the Britain's Strongest Man competition," says Kenneth. "He didn't think he deserved to be there as he hadn't done anything like it before, but he agreed to try."

Steven's training increased even further. It was all Kenneth could do to try and hold him back for his own safety.

If Kenneth added one weight for Steven to lift, the determined soldier added two more.

"He just pushed and pushed himself," says Kenneth. "He's very, very stubborn. But we know each other well enough that I know when to leave him alone."

It was at those times that both their military training kicked in. When Steven's grip failed once too often, or the pressure boiled over, Kenneth walked away as did the man fast becoming his friend.

As the day of the competition loomed though, both were optimistic.

"Steven went down and competed and gave it everything," says Kenneth.

The competitors tackled truck pulls, log lifts of 80kg and bore the weight of heavy stones.

At the end of it all, word of Steven's story had spread throughout the men he was competing against.

Among the thousands of people gathered that day, Steven received a standing ovation.

"The response has been great from others, especially from the other strongmen," he says.

"Compared to other sports, it really is one of those things where regardless of who you are, strength is strength, and there are definitely no egos."

But Kenneth wasn't quite done with Steven yet. "He bullied me into joining Facebook so I could look up other competitions to go to," laughs Steven.

So he did. And the one he found was going to be the ultimate challenge for them both.

It was the famous Arnold Schwarzenegger Classic - one of the biggest strongman events in the world - and it was holding its first ever 'disabled' category.

It was in Columbus, Ohio, in March 2017, and was to be one of the largest competitive fitness events in the world, created and hosted by Arnold Schwarzenegger.

The soldiers got to work. Arnie was waiting for them and they were determined to impress.

Inspired by Steven's resilience, Kenneth brought in a young man called Ruaridh M Turner, 23, who had trained with him before.

A documentary film maker, the trio decided to record Steven's journey to America.

"Documentaries really aren't my thing," admits Steven. "But I could tell it meant a lot to the guys and could do a lot for the sport so I agreed."

The goal was to film and showcase Steven's training and increasing strength.

It wasn't until the trio reached the airport though, for their flight over to the competition, that Kenneth and Ruaridh saw how much strength their friend really had.

"We had three connecting flights to take to get there," says Kenneth. "We had a massive walk between gates, and Steven flatly refused to take a wheelchair.

"I almost begged him to take one but he insisted on walking the whole distance instead.

"It was the first time I saw him in pain. He was sweating from the pain, but he refused assistance.

"That's the kind of guy Stevie is."

At the competition, Steven was one of the most severely injured athletes there. He still managed to bring home a 10th place victory overall.

The day culminated in the men meeting Arnold Schwarzenegger himself.

"It was a bit of a fluke really," says Steven. "Kenny was shouting like an excited teenage girl trying to get his attention, but it worked and he came over."

"It was a fantastic whirlwind experience," adds Kenneth. "I think it was really just the beginning for Stevie I think."

The Scots went on to gatecrash other parts of the event, leading them to meet the original Hulk Hogan.

The pair ended the night in the pub, using Steven's prosthetic legs as drinking horns.

"Definitely a good night," laughs Steven. "From what I can remember."

Back on Scottish soil, the pair are back in the gym again though - this time as Steven prepares for the 2017 British championship in a few months time.

From there, if everything goes to plan, his next goal will be to reach the World finals in September.

To an outsider, allowed a close-up view of what this will entail, it is a mammoth challenge, but one where victory isn't necessarily the main reward.

"I think this journey is for himself," says Ruaridh, who has been filming Steven's experience every step of the way.

"It's a personal journey for him regardless of where he places. It's not glory or pride. It's something personal."

The trio's film is named 'Improve Every Day', a take on the acronym IED for the deadly explosion which started it all.

A campaign to fund the film's release has been in its final stages, with the team hoping the whole amount would be raised in time.

"It's been a real journey. There have been a lot of changes in all of us," says Ruaridh.

"It's not just about lifting weights, this is a real human story. It challenges the ideas of disability and what that means. I don't view Steven as disabled, just adaptive. He can do it. He's just found another way and that is pretty incredible.

"These guys are very funny. Humour is a big part of it. And camaraderie. They have a friendship I would never really know or understand unless I was in the marines or the army."

The filmmaker, still a student in Edinburgh, says seeing Steven and Kenneth support each other has given him an insight into the bond these soldiers have, especially when they come home from war.

"They constantly adapt, push and support each other, but never take life too seriously," he says.

"It's fortitude of mind I think, and the ultimate kind of strength."