She has designed her life around reaching the summit of her sport, but when Kate Ziegler finally joined the most elite U.S. swim team last week she felt, suddenly, unprepared.

Everything around her seemed frighteningly new. Drug testers visited her twice within three days, once showing up at her family's house unannounced. An underwater camera stalked her during her first practices with the U.S. national team so that coaches could later dissect her stroke. A man in a white polo shirt squeezed blood out of her ear between laps so he could measure the lactates in her blood.

"The whole thing is pretty nerve-wracking," Ziegler said. "It's hard, because I'm definitely not a person who is good under pressure. I'm more of like a try-your-best type of person."

Pressure like this, though, is impossible to avoid: At the world championships in Montreal -- the swimming portion of which begins today -- the 17-year-old rising senior at O'Connell High will be seeded first in the 1,500-meter freestyle and fourth in the 800 freestyle. An unknown just two years ago, Ziegler is suddenly a favorite in one of swimming's most prestigious meets -- a distinction she is not necessarily comfortable with.

To live up to expectations, Ziegler must overcome bad allergies, a nagging ankle problem and asthma, as well as an elite international field.

"Obviously when you go into an event like this, you want everything to be perfect," said Ray Benecki, Ziegler's coach. "We're not quite there right now. We've had some problems we've had to work through."

The past three months have been some of the most difficult for Ziegler during her rapid ascent through the swimming hierarchy. Her club team, the Fish, moved practices outside at the beginning of the summer, and for Ziegler -- whose asthma worsens when she is subjected to grass, weeds, dust, leaves or pollen -- that felt a lot like moving to the top of Mount Everest. During light practices, she felt short of breath. During hard practices, she stopped for several minutes to recover.

Early last week, Ziegler went to see a breathing specialist she had previously visited. The doctor upped the dosage of one medication and added another. Ziegler took six asthma-related medications to Montreal.

There are other problems. Ziegler's ankles are weak and tend to roll inward, so she is undergoing physical therapy. Her calf muscles ache often. She has battled mild soreness in her shoulders.

As a result of her health issues, Ziegler's progress has slowed, if only slightly. She still managed to swim the fastest 1,500 in the world this year, 16 minutes 11.23 seconds at the Santa Clara Invitational. She also set personal bests in the 800 (8:30.68), the 200 (2:01.16) and the 100 (57.73).

"This year, I'd say 60 percent of her practices are better than last year, whereas last year she improved in 100 percent of her practices," Benecki said. "For almost anybody else, she's still improving very fast. For Kate, that's struggling."

Benecki and Ziegler are tackling the problem in their customary manner: by outworking everyone else. On the second morning of the U.S. team's training camp at the University of Maryland, the women's team scheduled a 90-minute practice. Ziegler's workout demanded more time, so she swam with the men's team for the last half hour of its practice. She climbed out of the pool again more than two hours later, the last woman to leave the water.

During Ziegler's practice, she stopped periodically for lactate tests. Genadijus Sokolovas, U.S. Swimming's director of physiology, pricked Ziegler's ear with a small needle, then squeezed blood onto a wallet-sized machine. Within 60 seconds, the machine measured the percentage of lactate in Ziegler's blood. Since lactates increase with workout difficulty, those readings showed how hard Ziegler was working.

"They also indicate," Sokolovas said, "that she's still a little bit tired."

Ziegler didn't seem to care. Now, she said, is not the time to feel tired. Her goals in Montreal are as lofty as the expectations of her: She wants to win the 1,500 or, at the very least, finish in the top three. She would also like to medal in the 800 and set personal-best times in both events. She hopes to swim the 1,500 in under 16:10; her goal in the 800 is to finish in less than 8:30.

"We always set goals, but I'm trying to keep the pressure a little off of her," Benecki said. "I can tell she's starting to get nervous. This is a different world for her."

And she'll enter it by herself. She left for Montreal without Benecki, her biggest swimming comfort. He'll fly in to watch her swim the 800 late in the week, but he'll miss the 1,500 prelims tomorrow and the final on Tuesday.

It's a decision Benecki made with painstaking calculation. Like a doting father, he is sometimes unsure when Ziegler wants independence. Benecki doesn't want to smother her; he doesn't want her to feel abandoned. Finding a middle ground is sometimes an awkward tug of war.

During training camp, Benecki adjusted his work schedule to attend almost every practice. He helped direct Ziegler through her workouts, even though a half-dozen coaches are assigned full-time to the national team.

After a Tuesday morning practice, Benecki asked Ziegler if she wanted him to come back for the afternoon, or if she would prefer a little more independence.

"Whatever you want," Ziegler said before walking into the locker room to change.

"It's hard to tell what's the best thing to do," Benecki said later. "I guess I'm not going to go watch the 1,500 unless she needs me. If she needs me I'll go. But I think she's ready for this, because this is what we've worked for.

"She can deal with some nervousness and being a little scared, even on her own."

Despite asthma, Kate Ziegler, 17, owns the fastest women's 1,500-meter freestyle time in the world this year. She has been practicing with the U.S. team in College Park, preparing for the world championships in Montreal. "The whole thing is pretty nerve-wracking," says Kate Ziegler, with coach Ray Benecki, of all the activity at the U.S. team's training camp.Ziegler, a rising senior at O'Connell High School, has her blood lactate levels checked at the U.S. team's training camp.