But some determined Irish women are now travelling abroad to compete in full Ironman events, while others will be taking on the half Ironman distance today in Dublin for the first time.
Maire Fox, from Ballylanders, Co Limerick, travelled to Austria in June with her boyfriend, Kevin Gilleece, to compete in an Ironman.
The laboratory manager, who trains with 3D Triathlon Club in Dublin, signed up because it was on her bucket list.
Maire (34) spent six months training, completing 15 hours of sessions a week at the peak of her preparations.
"I have a turbo trainer, a stationary bike, and because I rent a room in a house I'd to set up the turbo trainer in the garden shed.
"I was going out there on a cold winter's morning, setting up my turbo, and I'd turn on the tumble dryer just to get some heat for the first while until I warmed up. That was just so tough mentally getting up to do that. It was depressing to be honest."
Maire, who lives in Dublin, lost all drive to train when her father was diagnosed with cancer during her training.
"With two months to go, we got the news about Dad so all of a sudden I'd lost all motivation. That's when Kevin [my boyfriend] and Julie [my sister] were there to keep me focused. I knew Dad wouldn't like me to give up either."
But Maire, who has been competing in triathlons for the past eight years, said the sacrifices she made were worth it once she crossed the finish line after 11 hours and 56 minutes.
"I think I was at about 40k in the run when I saw Kevin and he gave me the Irish flag, and as soon as he did that, that's when the tears started to flow," she recalled.
Aine Donegan, from Garristown, Dublin, will take on the Ironman 70.3 Dublin today along with 2,600 competitors, one fifth (19pc) of whom are women.
Personal trainer Aine,(27) who recently left her permanent job as a nurse to pursue her new career, was inspired to take on Ironman 70.3 Dublin after seeing professional athletes competing.
"I started triathlons three years ago and I just really love them. I love the atmosphere and I really, really enjoy the training," said Aine, whose preparation was interrupted by a broken collarbone sustained when she fell off her bike.