Chrissie Wellington learned that grinning through the pain made her even stronger.

In a sport known for its gods and goddesses of the water, four-time Ironman world champion Chrissie Wellington started her first high-level triathlon in 2006 more like an anchor: Attempting to swim in a borrowed wetsuit that was many sizes too big, Wellington floundered and sank. She was rescued and hauled ashore in a kayak. “I was so reluctant to spend money on a sport I didn’t know anything about,” Wellington says with a laugh in a recent phone interview. “I was borrowing everything I could.”

So try something else?

No. After dealing with self-admitted mediocrity in a variety of athletic endeavors (“My gymnastics career came to a grinding halt in about 1985 when I realized that I had the coordination and balance of a baby giraffe,” she confesses on her website), Wellington knew she’d found a home in multisport. Despite her dubious debut, she rose through the ranks of the sport like a rocket—a talent-in-waiting powered by an engine of effervescent joy. Was it possible that a woman so skilled could also be having so much fun?

As a matter of fact, she was. The smile was genuine. The joy was heartfelt. “I was so grateful to have found something I was good at—a talent I didn’t know I had,” she says. “I was so excited!”

Her on-course goodwill was unfeigned, but it was also part of a naturally evolving strategy that fit Wellington’s gregarious nature. Wellington is a thinker. She is intellectually rigorous, with a post-graduate degree and on-the-ground experience in Third-World development. She genuinely likes, and feels for, people, and she found early in her career that by engaging with her audience during a competition, “like an actor on the stage,” she could turn a race into a performance, and a performance into a competitive advantage. “I’m buoyed by the response of the crowd,” she says.

She was also one of the most naturally talented long-distance triathletes to ever step on a race course—an endurance prodigy who found racing in Kona to be a “comfortably painful experience.” She won the Ironman World Championship there in 2007 as a rookie, surprising herself as much as the rest of the sport. “I didn’t have an understanding of what you were and weren’t supposed to do,” she says. “I just raced.” She would go on to win three more times.

Yet she hadn’t come from nowhere, exactly. Both on her own and as an employee of the British government, she’d been traveling to remote corners of the world for years, challenging herself physically at every turn. “If you do things like cycle for 10 days in the Himalayas at 5,000 meters for 10 hours a day,” she explains, “you cannot help but develop mental and physical strength that then manifests as a professional athlete.”

In her brief five-year career, Wellington built a competitive resume that reads like the bucket list for an entire army of elite triathletes. She bettered Paula Newby-Fraser’s course record in Kona and ran step-for-step with Mirinda Carfrae, one of the finest pure runners the sport has ever known.

Through it all she smiled, she laughed, she exulted. She cheered herself, the crowd, her competitors. She Blazeman-rolled across the finish line (you’ll have to look that one up). If you watched her race and found her joy to be infectious, well, that was mostly the point.

“I loved it,” she says.