You could say that Mike Wien is a late bloomer — athletically, at least.

A non-athlete earlier in his life, the 60-year-old east Cobb resident has transformed himself into an accomplished competitor as a runner and triathlete over the past decade.

The Peachtree Road Race is one of the competitions Wien has distinguished himself in, winning the 55-59 men’s age group last year.

Wien will try for another age group title — this time the 60-64 category — when he steps up to the starting line Wednesday as one of the 65,000 participants for the popular 10K race that starts at Lenox Square Mall in Atlanta and winds its way for 6.2 miles down Peachtree Road to the finish line on 10th Street next to Piedmont Park.

It will be the 15th Peachtree Road Race for Wien, who took part in the event for the first time in 1996.

For Wien, the Peachtree is an important part of his Fourth of July celebration.

“First of all, it’s a great way to celebrate the Fourth of July,” he said. “Every runner that I know in Atlanta is there. But, not only every runner — this is the one event of the year where some of the infrequent runners train for, so this is a celebration of healthy living.”

Wien hopes to duplicate, or possibly improve on, his Peachtree performance of a year ago when he led the way among men’s 55-59 runners with a time of 39 minutes, 13 seconds.

“It was a great race,” Wien said. “I was also 59 last year, so I was the oldest in my age group. One of my dear friends and good competitors, Bob Dalton — it was the first time that I had beaten him, so, it was a lot of fun.”

Wien has also made his mark in the Ironman Triathlon world championships in Hawaii, finishing as the runner-up in the 60-64 age group last October, as well as recording impressive finishes in the Boston Marathon.

None of these accomplishments seemed like even a remote possibility for Wien when he was growing up in Chicago.

Wien said his athletic career got off to a less-than-impressive start as a member of the Highland Park (Ill.) High School cross country team.

“I went out and lasted for three weeks, and then I quit,” Wien said. “My sophomore year, I joined the team and my coach called me a quitter. He didn’t give me a uniform or a locker for the first four weeks. I actually worked my way up my senior year to the seventh man on a five-man team. Seventh man on a five-man team meant that, if two guys died on the bus on the way to a race, I would get a chance to run, so I wasn’t much of a runner.”

After high school, except for a brief time when he ran some marathons in the late 1970s and early ’80s, Wien largely stayed away from athletic competition until he began doing triathlons about a decade ago — soon after turning 50.

“It was the whole idea that I was cross training,” Wien said. “I was swimming and biking. A lot of the guys I was training with were doing triathlons. I actually ran my first triathlon in 2002. It was sponsored by AARP for (athletes) 50 and over. I did well there and I graduated to the Ironman — the granddaddy of triathlons.”

Since then, Wien has competed in a number of Ironman triathlons — which includes a 2.4-mile swim, 112-mile bike ride and 26.2-mile run.

Wien’s proudest triathlon moment was his runner-up finish in the 55-59 age group at last year’s Ironman world championship, where he made a dramatic surge in the running portion of the race to secure second place.

“There were 39 in our age group, and these are all people who have won a race to get there from all over the world,” Wien said. “I came off the swim (in 10th place), I came off the bike 18th and I ran everyone down (on the running leg), except a guy from Switzerland.”

Wien also has fond memories of the Boston Marathon, which he has run eight times and where he ran a masters (40-and-over) personal-best time of 3:04:25 in 2010.

“I think Boston is one of the most exciting marathons there is,” Wien said. “The same thing as (the Ironman in) Hawaii — it’s one of the few races that you have to qualify. It’s the top of our sport, and I’ve been very fortunate to run eight Bostons.”

As a triathlete, Wien’s training regimen includes swimming, cycling and running.

“I do at least two different things a day, depending on the day,” Wien said. “Probably, I’ll swim five days a week, run four days a week and I’ll bike ride about four days a week.

“Generally, I’m training for marathons. So, certainly for marathons, I would like to run 40-50 miles a week. Right now, I’m probably in the 30-mile range, but I’m biking 200 miles (a week) and swimming about 8-10.”

Wien is looking forward to the Ironman U.S. Championship in New York on Aug. 11, where he hopes to qualify for the world championships in Hawaii in October.

For now, he is aiming for another strong showing Wednesday morning.

“I think, realistically this year, I’m looking to break 40 (minutes),” Wien said. “If the weather is just right, I could get 39, but breaking 40 minutes at 60 is what I would really like to do.”