But what is remarkable about Ledecky is her inner drive. A young woman with a gentle demeanor outside of the pool, Ledecky swims with an "aggression and the kind of fury" the moment she begins a competition. She's adopted a type of "galloping" stroke typically used by male swimmers like Michael Phelps, and has a "tough as nails" determination to be the best, according to her coaches.
"She's the greatest athlete in the world today by far," Michael J. Joyner, an anesthesiologist and researcher for the Mayo Clinic in Rochester, Minn., specializing in human performance and physiology, told the Washington Post. "She's dominating by the widest margin in international sport, winning by 1 or 2 percent. If [a runner] won the 10,000 meters by that wide a margin, they'd win by 100 meters. One or 2 percent in the Tour de France, over about 80 hours of racing, would be 30 or 40 minutes. It's just absolutely remarkable."
Like Biles, Ledecky has shattered world records. She is the current world-record holder in the 400-, 800-, and 1,500-meter freestyle (long course). She also holds the fastest times in the 500-, 1000-, and 1,650-yard freestyle events.
Also like Biles, Ledecky's Catholic faith is central to her identity.
Ledecky attended Catholic school - Little Flower School in Bethesda through 8th grade, and then Stone Ridge School of the Sacred Heart for high school - her whole life.
"My Catholic faith is very important to me. It always has been and it always will be. It is part of who I am and I feel comfortable practicing my faith. It helps me put things in perspective," Ledecky told the Catholic Standard in a recent interview.
She also confirmed that she says a "Hail Mary" before each event.
"I do say a prayer – or two – before any race. The Hail Mary is a beautiful prayer and I find that it calms me," she told the Catholic Standard.
After winning her first Olympic gold 4 years ago, Ledecky paid a visit to the convent of the sisters from her grade school, Crux reported. She wanted to thank the sisters for their support over the years, and give them a chance to celebrate with her.
Catherine Ronan Karrels, Stone Ridge's head of school, told Crux that Ledecky "is so grounded in her faith, and supported by a really loving family and community. She's an amazing young woman, who happens to swim."
Catch Biles and Ledecky this week and next on NBC as they compete in the 2016 Olympics in Rio.
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Mary Farrow worked as a staff writer for Catholic News Agency until 2020. She has a degree in journalism and English education from the University of Nebraska-Lincoln.