Edison Pena has prepared for Sunday’s New York City Marathon like no other competitor: running each morning and afternoon in steel-tipped electrician’s boots that he cut down to ankle-high shoes.

Mr Pena ran back and forth along a 1,000-yard path through the darkness and stifling heat and humidity inside the collapsed gold and copper mine where he and 32 other men were trapped for 69 days before last month’s dramatic rescue.

Mr Pena ran to clear his head, to push away his anxiety.

And he ran, fellow miners said, because he wanted to be ready to represent them in a marathon, where he might be able to spread a message about what he hopes will be the legacies of their ordeal: safer workplaces, closer families and more trust in God.

“If I had to run barefoot, I would have done it,” Mr Pena said after his rescue.

“Life has given us a new challenge – to care more deeply, to be more present with the people we love.”

Mr Pena, 34, has been among the more outspoken of the rescued miners, a man willing to show his emotions, even tears, as he talks of his intense desire that Chile’s mineral riches do not come at the expense of working people ordered into mines known to be unsafe.

“I would like things to change,” he said. “It was for something that I ran inside the mine. I think that things can be done. I think we suffered too much, that this too has to be worth something.”

Marathon organisers who learned of Mr Pena’s subterranean exercise routine invited him to come to New York to watch the race. They were shocked when he asked to run instead.

“Edison Pena will be one of the stars of this year’s marathon as he will be among the 43,000 or more runners at the starting line on Sunday,” said New York Road Runners spokesman Richard Finn.

Fellow miners were not surprised that Mr Pena wanted to run in the marathon.

Mr Pena ran twice a day, up to six to seven miles at a time, back and forth along the rocky, muddy floor of the gallery where the men were trapped, Omar Reygadas said.

Mr Reygadas was a distance runner himself while younger. Now 56, he said he and the other miners couldn’t keep up.

“We would rest and he would keep running. And then in the afternoon, he would go out and run again,” Mr Reygadas said. “He also would exercise and run with weight. He really did prepare.”

For the first 17 days after the mine collapsed above them, the men tried to contain their fears and save their energy, sharing tiny bits of food from an emergency supply meant to last just 48 hours and drinking contaminated water to survive. The worst moment was when they could hear the rescue team’s drill come close – and then uselessly miss their refuge.

“We thought we were going to die,” said Mr Pena, who nevertheless insisted that he never lost hope. “I always had faith to keep fighting, to stand up to things, to do what could be done.”

When they were finally discovered alive – and it became clear that their rescue could take months or more – Mr Pena got his perseverance back.

“During the first days, he didn’t have the strength or spirit to run. We didn’t have good food, we didn’t know what had happened. Our thoughts were on other things,” Mr Reygadas recalled. “Once food was reaching us, he started to run.”

Mr Pena has kept running since the rescue – including six and a half miles as part of a triathlon team event in Chile on October 24.