Five years ago, Bob Clark could barely walk.

Two months ago, Clark, who turns 62 on Jan. 17, completed the Ford Ironman event in Panama City, Fla.

That event consisted of a 2.4-mile swim, 112-mile bike ride and 26.2-mile run. The Butler resident finished the race in 14 hours and 55 minutes, placing 25th in the men’s 60-64 age group.

Diagnosed with throat cancer in 2005, Clark was declared cancer-free in 2006.

He’s been running for his life ever since.

“After his last operation, I flew in to see him and he couldn’t even walk a lap around the hospital floor,” Chris Clark, his son, recalled. “To even imagine my father doing this five years later — it’s crazy. But that’s how stubborn the man is.”

Chris Clark, who turns 41 on his father’s birthday, has had plenty to do with his father’s emergence as a runner.

He helped his dad train and completed the Ironman event with him. The younger Clark’s time was 11:54:06, placing him 188th out of 403 in the men’s 40-44 age group.

“Chris turned me on to this,” Bob Clark said. “He thought running would be good for me after dealing with my health issues.”

Chris Clark played quarterback at Butler High in 1986 and 1987. He was more of a running quarterback in high school who wound up operating a run-and-shoot offense at the U.S. Merchant Marine Academy.

While residing in Chattanooga, Tenn., the younger Clark started mountain biking. He competed in his first triathlon in 2001.

Clark was living in St. Louis when his father became ill. He joined Leukemia-Lymphoma Team in Training Society, which was preparing to compete in a triathlon to raise funds for cancer awareness.

“You had to fundraise at least $4,300 to get on the team,” he said. “I raised $5,800. I sent a letter to every family member and person I knew.

“My daughter had a 7-year-old friend who was fighting leukemia at the time. Between that little girl and my dad, I was motivated to do something through running,” Chris Clark added.

That motivation didn’t go unnoticed by his father.

“Chris inspired me with that whole thing,” he said. “He made me want to run, too.”

The elder Clark’s first step was a 2008 return to the Butler Road Race after nearly 20 years.

He’s run nine marathons since, is headed to Phoenix for a marathon in February and plans to run the Boston Marathon this spring.

“I’m taking a little rest after that,” Bob Clark promised. “But that doesn’t mean I’ll stop running.”

He rode a bike 100 miles on four different occasions while training for the Ironman. His son continued to train with his friends in St. Louis. When they could, father and son reunited and trained together.

Race day came Nov. 6. Chris Clark wanted to finish in under 12 hours. Bob Clark wanted to finish while maintaining his training pace.

Both succeeded.

“I can’t tell you how proud I am of him,” Chris said of his father. “Running the Ironman with him was so surreal for me. His progress is a fantastic story.”