HALE'IWA — As most of Hawai'i slept early Sunday morning, 15-year-old Cody Spraker and dozens of other triathletes pulled on swim caps and adjusted goggles beneath a full moon dipping into Waialua Bay.

Spraker and three other teens bobbed in knee-deep lapping waters, joking around until an air gun sounded — momentarily stifling crowing roosters and starting the 2009 Haleiwa Triathlon — shortly after 6 a.m. at Hale'iwa Beach Park.

The teens, all members of Hawaii Youth Triathlon Club and veterans of national competition, shot into the water, along with adult competitors, and swam 400 yards near Pua'ena Point. Within about one hour they would also cover 12 fast miles on bicycles and run three miles — including a stretch along a soft beach that can be unkind to tired legs. After pushing hard to finish in fifth place overall, Spraker quickly caught his breath and was laughing about the banter among athletes on the course.

"The fun part is being able to do these races with people you know," said Spraker, who has competed in more than 40 triathlons. His teammates, who crossed the finish line moments later, agreed.

"Being on a team can help" you improve as a triathlete, said Devin Rettke, 15. "I pushed him on that run today," he added, nodding to Justyn Raymond, 14.

Trevor Carlyle, 13, enjoys both the camaraderie and the individual side of the multisport. In triathlon, Carlyle said, "You know it's your fault if you didn't do well." And after a satisfying adrenaline-fueled race, "you kind of feel proud of yourself, and that raises your confidence."

The triathlon club's director, J.J. Johnson, traveled with the boys this summer to Colorado Springs for the USA Triathlon Junior National Championships. All four hope to one day — after their teen years, perhaps — compete with the world's top triathletes in the Kona Ironman.

But Johnson says podium snapshots and trophies amount to distant second-place to simply maintaining lifelong physical fitness.

"Triathlon is the catalyst for promoting health and fitness. That's really what it's about," said Johnson, 53, who has competed as a triathlete himself and takes part in workouts with the club's 65 members, ages 7 to 19. Johnson also serves as the Pacific Northwest regional athletic development coordinator for USA Triathlon — the accreditation source for 160,000 triathletes, including 20,000 kids.

The Hawai'i club's training routines are tied to preparing for an annual race series. Competitors dedicate 10 to 15 hours weekly to swims, bike rides and runs while prepping for races.

Club members are also encouraged to sign up for cross-country running and swim teams. Spraker, a kicker for Radford High's football team, gets in interval sprint training on the practice field. During winter months, he joins a swim team.

"I'll bike to swim practice as fast as I can for one or two miles," Spraker said, noting that the quick switch from pedaling to swimming helps with triathlon transition — those abrupt switchpoints from water to bike to land, which can leave untrained legs feeling fall-down wobbly.

Spraker, who started entering running events with his family as a kindergartner, signed up for his first multisport competition at age 11. "It didn't go as well as I had hoped. I entered the water first and was about the last to exit, and then I realized how hard it is to run in sand."

Since then, though, he has steadily grown into a triathlete, representing Hawai'i in three national championships and taking first place for the last three years in the club's annual race series. Even so, Spraker said maintaining a general fitness edge is the best prize the sport offers.

"I like to use triathlon to be completely fit," he said, "so I can choose to go to whatever sport I want to do."