You doubt there's iron running through her veins? Don't. Loke is in the Guinness Book of World Records as the youngest woman ever to complete the Ironman -- the Holy Grail of triathlons -- at eighteen. She's on her sixth consecutive year now and plans to keep the streak alive into her eighties. "You wake up on the day of the race and say to yourself, 'Oh, my God, I have to swim 2.4 miles, bike 112, and run 26.2,' " she says. "That's a lot to think about when you're just waking up." You can check out Loke on television this October when she competes on the Hawaiian Ironman course, which abuts her home in Kona. While you're watching, consider this: She's swum over a curious tiger shark, had her entire body stung by jellyfish, and been hit during training by a car that sent her bike flying eight feet into the air and deposited her on the hood of another car. And if that didn't stop her . . . "It took me a long time to say, 'Wow, I'm a triathlete,' " McMichael, twenty-three, says. "I always thought of those people as crazy."

--Esquire