It happens in every race.

That moment when every part of your body wants to call it quits.

Seattle's Andre Kajlich knows the feeling.

“That happens all the time out on a race,” Kajlich says. “You just have to, yeah, figure out a way to keep going.”

To keep going. Because you only get one life. No matter what happens.

In 2003 -- after a night with friends -- Andre was crossing the subway tracks in Prague.

“Driver came around the corner and was unable to do anything about it,” Kajlich says. “Saw me there and the train ran over me.”

Kajlich lost both his legs and nearly lost his life. But this former runner did not lose his will to live and compete.

Andre’s sister Anya recalls what happened in the hospital.

“I mean the doctors told Andre 'Sorry buddy, you might not sit again and you probably won't walk. Andre just thought 'Really? You must not know me very well," she says.

Ten years after his accident, Andre Kajlich is a world-class para-triathlete and ultra-endurance wheelchair racer. He's won both the Ironman and the Ultraman world championships.

“I kind of enjoyed a little bit of the fear of the unknown and finding out if I could do it and that sense of accomplishment,” says Kajlich.

His older sister Bianca, star of television shows Undateable and Rules of Engagement, wants to direct a documentary about her brother.

“I asked how it could be possible that he could be on a bike for seven hours--on a handcycle for seven hours-and I'll never forget what he told me which is that 'I just pretend that I will be doing this forever.'"

Forever may be exactly what the Race Across America feels like: Kajlich hopes to be the first solo hand cyclist to complete the 12 day, 3,000 mile race.

“Race Across America is a total monster. To best summarize I think what this race will do to you.More than one racer has quit with less than a hundred miles to go. Yeah. That's where it will leave you mentally,” says Kajlich.

“It's such an important story to be told,” his sister says. “For my family who has watched this young man broken in a hospital bed who didn't know if he would truly be happy again to this incredible athlete who inspires so many people and who inspires me on a daily basis.”

The Race Across America kicked off June 13, 2017 from Oceanside, California. Click here if you would like to help fund Bianca Kajlich's documentary.