Lisa Laiti, ranked No. 3 nationally in the triathlon, runs, bikes and swims a total of nearly 300 miles a week, every week.

There are no scheduled breaks in a professional triathlete's regimen. But compared with telling her parents she wanted to quit her job as a computer programmer last year to become a professional triathlete, working out is a walk in the park.

"It was a major decision for me to quit," she said the other day at her parents' home in Clifton, Va. "Especially around this house."

Her father, Dominic, is president of Hadron Inc., a computer company, and he wasn't particularly pleased about his only daughter, 25, running off to El Paso with her friend and training partner Todd Jacobs to train full time for the triathlon, a sport in which competitors successively swim distances from nine-tenths of a mile to 2.4 miles in open water, bicycle from 25 to 112 miles and then run distances from 6.2 miles to 26.2 miles.

"It took my dad a little longer to accept it," she said. "When I was a programmer, it was the way he thought things had to be: go to school, get a job. I have five brothers who live and work in the area; I was the only one to go off and do my own thing."

"I would have rather have her stay in Clifton the rest of her life," said Dominic Laiti, 55. "I think it was a reaction of questioning whether this really was the right thing to do. Generally, she knows what she's doing and sometimes we're not quick to understand."

But now, along with Jacobs, her father is her most ardent supporter. He even helped her find her current sponsor, FNN:SCORE, a cable sports network. Sponsorship is essential for a professional triathlete because only consistent winners make enough prize money on the circuit to survive.

Even then, sponsors and financial aid in some other form, such as free room and board, are necessary. To attend the events where most of the prize money is available -- the Bud Light U.S. Triathlon Series -- athletes must criss-cross the country from May through September. And those new to the sport, such as Laiti, must compete as often as possible to accumulate the points that translate into financial gain.

"A lot of the pros don't hit every USTS {event}," she said. "The well-established ones can pick and choose, so a lot didn't show at Houston {the second event of the series, May 17}. I finished fourth overall and that pulled me up to third in the rankings. It's important for me to do the circuit; that pretty much ranks you. Maybe next year, I'll do fewer. I'll worry more about the races with more money."

In the area at the end of June to prepare for the Baltimore Triathlon, she and Jacobs stayed with her parents. In El Paso, they stay with Jacobs' father on a military base.

Laiti says she has made $2,000 so far this year, and that Jacobs should make about $20,000 by the end of the season

Laiti was an age-group swimmer at W.T. Woodson High School in Fairfax and earned a swimming scholarship to James Madison University, where she achieved all-America ranking twice. She met Jacobs, who grew up in Kentucky and went to George Mason University, at the Burke swimming pool during a masters swim team workout two years ago.

After tentatively entering a few local triathlons as an age-grouper (a nonprofessional), Laiti turned professional and the two developed a strong bond. But Jacobs insists it isn't solely based on running, biking and swimming.

"We have a unique relationship," he said. "It's not triathlon related; we're always asking ourselves that. We just met in the pool and my lousy swimming attracted her and her good swimming attracted me."

Each had strengths the other lacked. Laiti helped Jacobs improve his swimming, which he categorizes as chopping and hacking. Jacobs, a talented runner through high school before injuries forced him onto a bike, assisted Laiti in her running, the weakest part of her triathlon.

Now, according to the U.S. triathlon series and the Coke Grand Prix rankings, Laiti is No. 3 nationally among the women, and Jacobs, 26, is ranked third among the men.

When the conversation gets around to equipment, which it invariably does with triathletes, Jacobs, a pro for three years, becomes the spokesman. "The women watch the men," he said. "They're not developing things like the men are. The men hate each other; the women are a little more friendly. We'll edge a guy off the road. We'll set him up for a drafting violation {in cycling}. I'll yank a guy's {neoprene suit} zipper down, absolutely."

Competing in the triathlon cannot be done cheaply at the elite level. The athletes' ultralight carbon-fiber bikes each cost more than $2,000 and a carbon-fiber-disc wheel (no spokes to eliminate air drag) is $500. Cycling suits run $200 and helmets are $40-$50. That total doesn't include swim suits, running gear and shoes, some of which exceed $100, and other incidentals.

"It's strange sometimes because my friends and peers actually have things," said Jacobs. "We don't. Our bikes are more expensive then the car we have. But there comes a time when you have to define your part in the sport, whether you're going to stay an age-grouper and work to give it your all. You'll find out pretty soon if it was worth it."

Invariably, with more people each year entering ultra-endurance events, they are asked why they want to endure it. Why they run 20 miles in 120-degree heat at altitude (in El Paso); why they subsist more on adrenaline then on food.

Said Laiti: "When I was working, I didn't enjoy life."

"It only takes one car and then you'll be working again," said Jacobs. "The worst thing would be not being able to do this, not being active. I went through it once. I don't know; maybe if I had a college running career and achieved my potential there, I probably wouldn't be doing this."