Mark Geoghegan had not even tried a triathlon until May of 2002. Now, he can't get enough of them.

In fact, the Australia native, now living in Hawai'i, is going to do three world championship triathlons in the span of three weeks.

In a saga that is comparable to Frodo's journey to Mount Doom, Geoghegan's epic begins next week Sunday with the 2005 JAL Honolulu ITU Triathlon World Championships, followed by the Ironman Triathlon World Championship Oct. 15 in Kailua, Kona and wraps up with the Nissan Xterra World Championship Oct. 23 on Maui.

Geoghegan reverently refers to it as the "Hawai'i Worlds Triple."

All told, that adds up to about 7 kilometers (about 4.3 miles) of swimming, 63K (about 39 miles) of running and 250K (about 155 miles) of cycling.

"It's pretty ridiculous," the 41-year-old structural engineer said with a sheepish grin. "But it's a unique opportunity. (The races) cover the full gamut of triathlon."

Each race presents a different challenge. The ITU Triathlon is a shorter, faster struggle around Kapi'olani Park, while the Ironman's extreme length — it usually lasts between nine and 11 hours — is the epitome of an endurance test. The Xterra's rugged biking and running trails, meanwhile, test the triathletes' offroad capabilities.

Geoghegan considers it a once-in-a-lifetime chance because the ITU Triathlon, otherwise known as the Age Group Worlds, rotates its location worldwide from year to year.

His goal is to place in the top 10 in his age bracket in the ITU, where he'll be running with Team USA, and within the top 25 in all three races.

He has participated in more than 10 triathlons over the past six months — "I can't remember exactly how many," he said — one in Australia and the rest throughout Hawai'i. He's lived here since 2001.

A father of four daughters ranging in age from 7 to 13, Geoghegan's exploits have become contagious. All four kids have competed in at least one keiki triathlon.

Admittedly, it can be hard for him to find time to balance family, work, and training.

"My family has been kind enough to extend me some slack," he said. "They've been understanding."

Geoghegan owns his own engineering company, so he makes time for training wherever he can find it.

He trains about seven to 10 hours a week now, in the "tapering off" period before the ITU. He'll focus his training toward the Ironman by running at noon to "climatize to the race conditions." He won't burn himself out, but that doesn't mean he won't go on three-hour plus runs and biking trips.

As for the offroad Xterra, he said he hasn't done a whole lot of mountain bike training but, "that should be a hell of a lot of fun."

He's proved he can have success in the Ironman — he was the top overall finisher from Hawai'i last year. But that was also the only one of the three championships he attempted. Still, he's looking forward to the three trials.

"The three (championship races) are never going to happen again (here) in my lifetime, so I might as well do it," Geoghegan said.

It's just a matter of pacing yourself.