"I'm opposed to this notion that exercising is only for skinny people," Mirna Valerio tells PEOPLE
Mirna Valerio does not look like your typical long-distance runner and she knows it.
The 39-year-old with a passion for running is the founder of the popular "Fat Girl Running" blog, which she uses to document her athletic accomplishments as well as offer advice for runners of all levels.
“I would love to be somebody who helps to shatter that stereotype of who’s a runner and who’s not, and who’s able to do this and do that,” Valerio tells PEOPLE. “I’m opposed to this notion that exercising is only for skinny people.”
The Georgia resident says she first found her love of running in high school, when she played on both the field hockey and lacrosse teams. She kept up her running habit for years after that, but eventually just stopped.
Then in 2008, she thought she was having a heart attack.
“I was over 300 lbs.,” she admits. “I was having pains in my chest and was hyperventilating. I had my son in the car and I was very scared. It was a traumatic experience.”
Fortunately, it was determined that Valerio was not having a heart attack, but she did have inflammation in her body and high blood pressure.
“I followed up with a cardiologist, and he was the one that said to me if I wanted to see my son grow up, then I was going to have to change,” she says.
So Valerio began running again, and hasn’t stopped since.
“Running is hard, and I like doing things that are hard for me,” she says. “I also love doing things that people don’t expect – not just for them or for the shock value, but I just love doing it.”
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She also truly enjoys the actual experience of running.
“I love being outside, I even love being on the treadmill,” she says. “I just love being able to move my body in the way that it was intended to move. And it has brought me so much joy. It just makes my body feel really good. And there definitely is that sort of runner’s euphoria after most of my runs. You go back because you want to get that feeling over and over again.”
Through running, Valerio has dropped over 40 lbs., but now she just does it to keep challenging herself. She has already completed numerous marathon and ultra-marathons.
Valerio reminisces about completing the Finger Lakes 50K trail race – in the rain – in 12 hours and 16 minutes.
“I came in last, but I didn’t care,” she says. “I got a lot of cheers. I’m slow, but I can just go on forever!”
Valerio, who works as a teacher, hopes to inspire others of all shapes and sizes to be active and do what they love.
“I’ve gotten so many emails and comments on the blog, on Facebook and Instagram about how much just being myself has inspired a lot of people,” she says. “I wasn’t aware that people had so many issues with showing their bodies outside, so a lot of people have told me that my being out there has given them permission to be out there, or to try running, or to start walking outside. That kind of response is really overwhelming.”