At 67 years old, Paul Butler will be swimming, biking and running more than 70 miles Sunday.

And it isn't because his company, ESi, is sponsoring the Ironman. It is because he is an ironman.

Butler, the chief financial officer for the Augusta-based software company, has participated in 19 Ironman events since he turned 60. In his 50s, he competed with his son in an adventure racing team.

"Because of my association with the Ironman, becoming the sponsor was a natural," Butler said.

The ESi Ironman 70.3 Augusta event will take place Sunday. More than 3,300 athletes are entered. The 70.3 represents the number of miles, and is half the length of a regular Ironman triathlon.

Butler loves the full length. He's done two of those this year, in South Africa and Australia.

His office on the 10th floor of the Wachovia building has photos of his Ironman experiences. He's not smiling in any of them.

"It is probably mile 80 where you really begin to say, 'Why am I doing this?' Even the pros, no one has an easy time with these things. You don't smile very often," Butler said.

When getting ready for an Ironman competition, Butler is training 20 hours a week or more. Even when he's not getting ready for a race, he never does less than 10 hours a week running, biking or swimming. He swims an average of 8,000 meters a week.

The former Army major, who served four years in Vietnam as a Green Beret, retired from 20 years of military service in 1984. He went into business for himself brokering deals between U.S. firms and foreign governments. His father was a diplomat and so he grew up in Turkey, Switzerland and Israel.

"There's one thing you can do from any hotel anywhere in the world: run," he said.

Butler got more extreme than marathons in the 1990s when his son invited him to be a part of his adventure racing team.

The multi-day races involve mountain bikes, kayaks, climbing and running. And they usually involve little sleep during the three days.

"When I was 56, my team won the Florida Coast to Coast, 72-hour race. I was 20 years older than anyone else on my team," he said.

He left adventure racing in 2002 when he hallucinated in the middle of the night during a mountain bike leg on a rocky trail.

"Age can't handle sleep deprivation," Butler said. "I can't do all-nighters anymore."

Ending that career opened the opportunity to do something he'd always wanted to do.

"I had always wanted to do an Ironman. How can you run a marathon after you've been on a bike for 120 miles?"

After six months of training, he did it, finishing a New Zealand Ironman race in 15 hours.

"I already had great endurance and discipline. All I had to do was swim for the first time in 40 years," Butler said. "The first time is a really scary thing. You have no experience as to what this does to your body or your mind."

It takes about six weeks to fully recover from one.

His best time was 13 hours and 15 minutes in Brazil, when he was 63.

"I have been getting progressively worse each year that I get older. People in their 30s and 40s can look forward to improving every year. I'm as strong as I ever was, but my capability to process oxygen begins to go. I can do nothing about that," he explained.

Butler said he won't stop competing until he can no longer finish one in less than 17 hours, which is necessary to receive a medal.

Even when there are no Ironmans in his future, Butler believes he won't stop moving.

"I really enjoy swimming. It is low impact. I think I can probably swim to 90 years old."