288-Lb. Woman Becomes Heaviest to Run a Marathon and Aims for Ironman: 'It's About Visibility'

When Ragen Chastain sets a goal, she wants it to be nearly unattainable. Which is how she went from hating running to signing up for a marathon.

“I decided I wanted to try a challenge and jump out of my comfort zone, and distance running had always been the thing that I was worse at in the entire world,” Chastain, 41, a speaker and writer, tells PEOPLE. “So I signed up for a marathon first thing.”

Plus the Los Angeles-based Chastain, who weighs 288 lbs., wanted to bring visibility to runners of different sizes.

“I was looking around for other plus-size people who had done marathons, and I saw a lot of people who started the marathon but didn’t finish it,” she says. “So I was just really inspired by the idea of being plus-size and finishing the marathon, and the visibility that would create for other people who wanted to try it and thought they couldn’t because of their size.”

After completing a 20-week training program, Chastain successfully (if not painfully) finished the Seattle Marathon, only to discover that she could’ve set the Guinness World Record for the heaviest woman to run a marathon. Because it’s not possible to set the record retroactively, Chastain would have to run another one, which didn’t sound appealing at the time. But, ever the goal setter, she decided to shoot even higher.

“I was having trouble psyching myself up to do another one, honestly, so I listened to audiobooks about endurance athletes and a lot of them had completed Ironman triathlons, so I wondered if I could do that,” she says. “It seemed like the ultimate expression of pushing outside of my comfort zone. So I decided to do the second marathon as part of the training for Ironman Arizona.”

Chastain says her training for the Ironman — which starts with a 2.4-mile swim and a 112-mile bike before ending with a full marathon — made the marathon preparation much more enjoyable, and she was able to get the Guinness World Record at the Mainly Marathon in Sanford, Maine.

She’s now excited to continue prepping for Ironman Arizona in November, and wants to continue pushing the boundaries of what is considered acceptable for women of her size.

“Nobody of any size is obligated to participate in fitness, but I think that we should all be welcomed,” Chastain says, adding that she’s dealt with criticism from people online who say she’s promoting obesity.

But Chastain sees their comments as proof that she’s doing the right thing.

“It’s a good indication that the work that I’m doing is not only necessary but effective,” she says. “And 10,000 emails from trolls are wiped away with one email that says, ‘I’ve always wanted to run but I was told that I couldn’t do it at my size but I saw what you did and signed up for a 5K,’ or ‘I’m going to marathon now.’ So much of it is giving people role models.”