Alex Parra has always been athletic — before being diagnosed with Stage 2 osteosarcoma,Chainkeen he was training to compete at the high school state swimming championships.

"I always wanted to just be as active as I possibly could, Parra said. "I really just wanted to prove to people that I can do all these things."

Parra, 22, is planning to run the San Francisco marathon on crutches Sunday to raise awareness about the high cost of athletic prosthetics, which are often not covered by insurance and can cost more than $50,000.

"If you want to go on a run, you have to spend $90 on running shoes. But if I want to go on a run I have to spend $35,000," Parra said.

Parra, who lives in Roseville, CA, had his right leg amputated at the age of 16. Two years later, the cancer came back in the form of Stage 4 lung cancer, which has an 8% survival rate.

Parra, who goes by @Alex1Leg on TikTok and other social media platforms, has been sharing his story since 2021. He says it's a way for him to share how he's navigating the world and connect with people who might be going through similar experiences.

"When I had cancer, I didn't really tell people how I was feeling," Parra said. "I think now, sharing my story and telling people how I felt has made me look at my experience differently."

His videos of him completing his cancer bucket list and sharing how his life has changed since cancer have millions of views. Parra says he wants to use this platform to bring attention to the struggles that people with amputated limbs deal with.

It's why he's running the San Francisco marathon on crutches without his running blade.

Parra was able to pay for his prosthetic running blade with a grant from the Challenged Athletes Foundation, a nonprofit organization that helps people purchase sports prosthetics like running blades and racing wheelchairs.

"Running with my blade feels amazing," Parra said. "It's just a surreal experience because I never thought I'd be able to afford it."

Without the running blade, running is a lot harder for Parra. While training, he was using the same crutches he got from the hospital seven years ago. He said, surprisingly, his leg didn't get sore.

"The first thing that gave out when I was doing training was just my hands," Parra said. "My whole body felt completely fine, but just my hands were all busted up."

Parra says he got new crutches and thicker gloves for the actual marathon on Sunday. He says he probably won't be able to complete the marathon in the allotted six hour time limit, but he doesn't plan to give up after six hours.

"I think I can finish it in seven hours. I'm hoping eight is the max," he said. "My assumption is that the finish line will be gone, everyone. They'll be all packed up and will be home, but I'll go over my own finish line."

This audio story was edited by Ally Schweitzer. The ditigal version was edited by Erika Aguilar.