OKLAHOMA CITY - Each year, more than 24,000 people take part in the Oklahoma City Memorial Marathon, to remember those affected by the bombing. One of those runners this year is determined to finish the race, despite her health obstacles.

With every step and every breath, Ruth Rickey keeps moving.

"I'm like the healthiest sick person you'll ever meet," she said.

The effort isn't easy but necessary, which is why she's become known as "Relentless Ruth."

"I start a lot more races than I finish," Rickey said. "Something about being out there and being outdoors makes me feel alive."

Ruth suffers from a rare form of leukemia and Addison's disease.

"It turns out that Addison's is a lot harder than leukemia," she said. "If I'm not on steroids, I don't get out of bed, I can't move, everything hurts."

However, she's managed her health and has become a triathlete in her own right. And now, she's now training to honor the victims of the Oklahoma City bombing with survivor Amy Downs by her side.

"They lost 18 employees and Amy was buried alive," Rickey said.

The two women work together at Allegiance Credit Union, formerly the Federal Employees Credit Union that was on the third floor of the Murrah building. After her long recovery, Amy returned to work and is now the CEO. The coworkers she lost are remembered in a garden outside.

"I couldn't walk away if I wanted to because I've been through so much," Downs said about returning to work. "One hundred twenty-five of the people who were killed were members of our credit union and I see them all the time, their families and I know the stories behind each one of them."

"Hundreds of these stories of resilience have surfaced following the Oklahoma City bombing, inspiring tens of thousands of people to run each year in the Memorial Marathon.

"When you're training and your running with people and you start talking to them and you find out the huge life challenges that they have had, that they have overcome, it gives you hope," Downs said.

It's this same hope she finds in Ruth and this year, the they plan to cross the finish line together.

"It is just so exciting because you know that you did it, you set your mind to something and you consistently trained, and you accomplished it," Downs said.

"People lost their lives and were forever changed and if I can be out there, next to her on the course in a couple of weeks than that's going to mean everything," said Rickey.

The Oklahoma City Memorial Marathon will be held on Sunday, April 29. You can follow Ruth's journey through her blog, Relentless Ruth, Leukemia Warrior: Living Beyond a Diagnosis https://therelentlessruth.wordpress.com/2018/04/12/ruths-back-story/