Running Phenom Mary Cain Makes Move To Triathlon

After setting national records as a high schooler and rising to running fame, the 25-year-old has now joined Paulo Sousa’s Triathlon Squad and will race for her pro card in Clermont, Florida this weekend. 

Photo: Laurel Wassner

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Yes, Mary Cain wants to be a pro triathlete. But no, she doesn’t want to be the next Gwen Jorgensen. Or Beth Potter. Or even Alex Yee, for that matter.  

Because while it’s a logical step to draw comparisons to other top-level runners who have made impressive crossovers into triathlon, Cain, who will launch her season this weekend at the Clermont Challenge, a draft-legal race in Florida, is approaching this venture with a measured dose of humility and reverence. And the 25-year-old running phenom wants to be sure that the world knows she’s not quite ready to, well, set the world on fire. 

“It would be a huge disservice for all of the women who are already out there kicking butt for me to say, ‘I can swim and run. I’m going to be really good at this,’” she said. “I have a lot to learn and far too much respect for athletes who have worked tirelessly in the sport for me to just think I can jump in and be the next best thing.” 

That’s not to say Cain doesn’t have the chops—or the athletic IQ—to do very well in the sport. On paper, she certainly checks the boxes of a superb triathlete. To start, she’s a strong swimmer, thanks to a childhood and adolescence spent following the black line on a competitive team in her hometown of Bronxville, New York. “I could have probably gone D1 as a swimmer,” she said of her potential in the pool. “By seventh grade, it was becoming apparent that I’d be a better runner.”  

Indeed, Cain became the most successful teen runner that the country—or even the world, for that matter—had seen. At 17, she became the youngest American athlete ever to represent the U.S. at a track and field world championships, and later the youngest to make a final in the same meet when she finished ninth in the 1500m. Her national high school records in the 800m (1:59:51), 1000m (2:35:80), 1500m (4:04:62), 3,000m (8:58:48), 2-mile (9:38:68), and 5,000m (15:45.46) are still standing, as is her world junior record in the 1,000m. After graduating from high school, Cain signed a sponsorship deal with Nike, foregoing her collegiate eligibility in exchange for racing professionally around the world.

Her meteoric rise and resounding success as a young runner was later shrouded by scandal following her heartbreaking revelation that she had suffered emotional and physical abuse under coach Alberto Salazar, triggering a downward spiral of disordered eating and depression. In the years following, Cain moved from Portland to New York and continued to run while working as the community manager at Tracksmith, launched a nonprofit, and started a professional running team. Given how busy she was becoming, and considering everything she endured in the public eye, it would be understandable if she opted to place competitive athletics squarely behind her.

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Still, Cain couldn’t ignore a tug towards the pool; recalling with fondness how swimming was the one sport that she truly loved and “really felt part of a team.” At the same time, she had a growing curiosity about triathlon, wondering what she could do if she put her two strengths together (and, yes, learn how to race on a bike, which she’s diligently working on). She raced the bike leg on a celebrity team in last September’s Malibu Triathlon and also placed third overall at a low-key sprint in Miami the same month, posting an 18:04 5K split. But neither experience, though enjoyable, was enough to solidify her decision to pursue triathlon whole-heartedly. 

Mary Cain is working on her biking as she tackles triathlon. (Photo: Laurel Wassner)

So in November and December, she took six weeks off of exercise entirely, focusing on other aspects of her life and letting a couple lingering running injuries heal. She also allowed herself to dream big about her potential as a triathlete. “At the end of that break, all I could think about was triathlon,” she said. “I love the training, it’s fun, and I decided, yeah, I really want to pursue this.” 

Since then, Cain has been quietly making inroads in the sport; first connecting with a cadre of pro triathletes and fellow New Yorkers like Laurel and Rebeccah Wassner, whom she swims with. She also began talking to elite coach Paulo Sousa, and last month traveled to Portugal to meet and train with his Triathlon Squad, which includes 2020 Olympian Summer Rappaport. The trip went well, and bolstered Cain’s confidence that she can compete with the very best.

Others see it, too. “It’s not a question of if but when Mary will turn pro,” said Rebeccah Wassner. “She’s already at that level. She’ll figure out the technical aspects quickly because she has a good attitude about learning from those around her. She’s motivated, she knows how to train hard, and she’s willing to put in the work.”

Now officially part of Sousa’s squad, Cain says she is ready to re-enter the arena of professional athletics—and accept the intense scrutiny that can come along with it. And after months of remaining reticent about her plans, finally publicizing her triathlon journey, she said, is a “monkey off her back.”

“At first, I was holding back in sharing this thing I was falling in love with because I was scared of what other people who don’t even know me were going to say,” Cain, who has been a lightning rod on message boards and social media for years, said. “I’m so excited to see where this takes me and to try to compete at the highest level possible for me. But honestly, I have no idea what that is going to be.” 

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