A little under five years ago, Conor Fitzgerald would have felt out of breath watching the runners pound the pavements in the Dublin City Marathon. But on Monday, as over 14,000 people weaved their way through the city to complete the 26.2 miles, the Wicklow man could be forgiven for being a little smug.
The back-to-back 2.4-mile swim, 112-mile bike ride and 26.2-mile marathon took him 13 hours and 24 minutes to complete, despite vicious rain, thunder and lightning which slowed down all the competitors.
"I have never done a marathon by itself," says Conor. "So I would be interested to see how fast I could do it. The joke among Iron Man competitors is that marathon runners have it easy, because they don't have to start the race directly after cycling 112 miles."
After completing two Iron Man competitions this year, Conor freely admits that not so long ago when he walked into his local gym the trainers probably laughed at him. Back then he was 5' 9" and feeling every pound of the 16 stone he weighed.
However, despite his bloated size, Conor was determined to train for his first triathlon, a gruelling race made up of a 1.5km swim, 40km cycle and a 10km run.
"I think the trainer was in shock," he says. "When he asked me to run on the treadmill to gauge my fitness, I couldn't even complete 100 metres."
In school, Conor had been a competitive swimmer and did the usual sports, such as rugby and football.
"Fast forward 20 years later and my business [Conor is a supplier of tools and equipment] was doing well, but the weight started to pile on," he says.
"Then in February 2009 I was kicking a ball on the beach with the guys and I ended up collapsing. I thought I was having a heart attack."
When he eventually got his breath back, one of his friends, recalling how Conor used to be a swimmer in his school days, suggested he should target a triathlon to get in shape.
"So, without really knowing what I was getting myself into, I said 'yes'," he laughs. "So, when I joined the gym I was put on a 14-week programme at the end of which I did a triathlon in Athlone. And I was hooked after that. I had lost about one-stone-and-a-half and thought I was in great shape. But that race was four years ago. Now, I am just over 11 stone and I don't find it hard to maintain that weight. And my waist is size 30. It is like being 18 again."
Conor is not alone, however, in his transformation from what he calls "fatlete to athlete".
Middle age for men may have typically been a feast of potbellies, pinstrip suits and pumped-up sports cars, but the modern Irish male has been beating their midlife crisis by jumping into body-hugging Lycra and cycling, swimming and running their way to fitness.
The triathlon is now one of the fastest growing sports in the country, with an 800pc increase in participants since 2005, according to figures from Triathlon Ireland. The majority of participants are male and aged between 35-42.
Joining this growing sport, however, was not easy for Conor, especially as he battled to lose weight.
But the one thing that kept him going and still keeps his motivation burning bright is a photograph hanging on his wall at home.
"At Christmastime when I was carrying my baby daughter, Alison, into my parents' house they took a photo and gave it to me," says Conor. "They thought it was a wonderful snap, but it was that picture that really pushed me over the edge. I cannot believe the size I was. Now I keep it to remind me never to go back."
After transforming his life, Conor is proud to be considered a Mamil (middle-aged man in Lycra), a term used to capture the rapid rise in men turning to competitive sport rather than swanky sports cars to cope with mid-life.
But achieving the adulation that comes with winning a medal does come with a price.
"It is not a cheap sport because you quickly get sucked into the bike porn and the gear," says Conor. "You have your carbon fibre bike, and they start at about €1,800. Then you have all your Lycra gear, your gels, power bars, energy drinks, your club membership, physiotherapist bills and so on. It can be endless. Race entry fees in Ireland average around €50 and Iron Man competitions cost between €250-300. So, you can either set yourself a budget and stick to it, or blow an awful lot of money."
After putting his body to the test in Challenge Barcelona, just days before he turned 41, Conor is now going to take it easy for a while and catch up on work after putting a huge amount of energy and time into his sporting passion.