An Ironman Who's Not Yet a Man

Lussi shaved 1 hour 46 minutes off his finishing time this year (13 hours, 41 minutes, compared to 15:27 minutes in 2007). He hopes to trim more in 2009. But after meeting Michael Phelps's longtime coach Bob Bowman last month, Lussi's aspirations have grown even higher.

"London is the goal," Lussi said, referring to the 2012 Olympics. He hopes to qualify for either the triathlon or the long-distance, open-water swim. And he has started working out a few days each week alongside Bowman's proteges, including 2008 Olympian Katie Hoff, in Baltimore.

According to Bowman, Lussi has the stroke of a classic long-distance swimmer, with high elbows, good tempo and minimal kicking, which also helps him as a triathlete, sparing legs for the rigors of the bike and run.

Like Rogers, Bowman sees no reason to bar Lussi or any uncommonly gifted youngster from long-distance triathlons.

"I kind of feel like young people are suited to endurance-type activities," Bowman said. "Clearly the danger is that you push them to the point that they are overly fatigued and get injured. But as long as the program is sensible and thought out, they can pretty much do anything they have their mind set to."

For too many American youngsters, exercise is an all-or-nothing proposition. At one extreme, children get far too little exercise, and studies show that such inactivity contributes to chronic health problems later in life. At the other extreme are children who specialize in a given sport too early and train to an excess, leading to burnout and overuse injuries.

New federal guidelines issued in October called on all Americans to exercise more to combat the risk of heart disease, stroke, high blood pressure and diabetes. Children and adolescents, the guidelines advised, need at least one hour of exercise each day, with vigorous activity to strengthen muscle and bones at least three days a week. Skateboarding was cited as an example of moderate exercise; biking and soccer, intense exercises.

The ranks of triathletes have grown steadily since the sport was added to the Olympics at the 2000 Sydney Games. In the past two years alone, membership in USA Triathlon jumped nearly 40 percent, to 113,000. Pop diva Jennifer Lopez recently did her first triathlon. Washington Mayor Adrian M. Fenty is a triathlete, as is President-elect Barack Obama's chief-of-staff Rahm Emanuel.

According to Bob Seebohar, a dietician with the U.S Olympic Committee, anyone can do a triathlon with proper training, which means progressing at a measured pace from shorter distances to long. Not only do triathlons promote physical activity, he argues, but they also promote discipline.

"The biggest thing is the accomplishment of setting the goal and crossing the finish line," said Seebohar, who also competes in Ironman events. "It's the biggest adrenaline rush that exists, at least in my mind. It's such a positive thing when you cross that finish line -- a sense of accomplishment, or pushing the body further and further."

In Hunter Lussi's case, the progression to ultra-distance triathlons happened fast. He did his first Olympic-distance triathlon at 10. At 12 he did a 70.3-mile triathlon, commonly known as a "half-Ironman," and learned a valuable lesson about pacing himself while battling three-foot waves and withering heat and humidity.

"I was still a kid," Lussi recalled, "and I thought about getting out. But my dad said, 'You can do this! You're trained for this!' But it was brutal."