Newtown’s Irene McCarthy isn’t your average 82-year-old. She works part-time and exercises regularly. We’re not just talking about walks around the block either. As of June 15, McCarthy is a competitive runner.

McCarthy ran her first road race, the 39th Annual Rocking Rooster Run, a 5K, this past week. She’s almost four times the age of Rooster Run winner Kevin Hoyt (22), who has run in countless races. Hoyt’s time was ultra impressive (15:09) but it wasn’t nearly four times as fast as McCarthy’s.

McCarthy finished the 3.1-mile course, which started and finished at Fairfield Hills near the Newtown Municipal Center, in a time of 38:52. She was 372nd among 464 finishers; just completing the run/walk is feat in itself for anybody, never mind a person in their 80s. McCarthy finished second in her age category, the 60-and-over female grouping, outdone only by 67-year-old Southbury resident Joan Manfredonia. So why now, at 82 years old, did McCarthy decide to lace up the running shoes and take on a competitive edge?

“I thought it was time I started my bucket list and my bucket list said I’m going to do a half marathon,” the spry McCarthy said just minutes after completing the Rooster Run.

“I’ve looked at the training for a half marathon but I don’t think I’m going to make it in my lifetime,” she added.

Heck, not many 80-somethings do a 5K, so McCarthy has still earned the envy of many athletes and nonathletes alike. And given that McCarthy did the 5K, she may just surprise herself with a half marathon finish sometime soon.

Her eyes-wide ambitious idea of a half marathon (that’s 13-plus miles by the way) led to doing the 5K.

“I’ve walked for a long time and I used to [walk] on the treadmill all the time, and then when I finally decided that if I wanted to do a half marathon, I have to get out into the road. And so I went online and looked for a training program for a 5K and that’s what I use,” McCarthy said.

She began her Rooster Run training six weeks ago and came a long way in a short time, although this new runner has higher expectations for herself. She was attempting to run 12-minute miles in the race. McCarthy finished with a pace of 12:30. “The long hill after the ballpark — that’s a loooong hill to climb,” she said of the grueling stretch past Glander Field.

Even despite that hill slowing her (and it added to the time of many if not all of the participants), “this is my best time,” McCarthy said of running 3.1 miles.

The 82-year-old had the support of her granddaughters, Amelia and Margaret McCarthy, who flew in from Godfrey, Ill., to run along with her. McCarthy urged them to run ahead, but her grandchildren stuck with her from start to finish.

McCarthy said family members couldn’t believe what they were hearing when she said she signed up for the 5K, but they were all very supportive of her endeavor. Once she registered there was no question about whether or not she would follow through. “When I part with my money I’m going to use it,” she said.

“I’ve been trying to keep up with her for 60-some years,” Dennis McCarthy, Irene’s husband, said with a laugh. “She keeps at least a quarter mile ahead of me.”

McCarthy’s secret to running success at her age, in addition to her training: “I try to eat healthy, I eat things like yogurt and nuts, and cheese. I don’t eat much meat — mostly vegetables.”

What’s next for McCarthy? “I think I’m going to keep training and maybe I’ll try the September one,” she said of the Newtown Road Race. “I’m training myself so I don’t have anybody to push me.”

So McCarthy pushes herself. She does that anyway; the 82-year-old works part-time as an administrative assistant for a dental office and her house keeps her busy, too. Her son, Mike McCarthy, is the tree warden in town. Irene McCarthy has been a Newtown resident since 1971.

You may wonder what else is on that list of McCarthy’s, but you stand a better chance of getting 3 miles out of her than an answer.

“She’s a hard woman to keep up with,” Dennis McCarthy said lightheartedly.