As a kid, she didn’t even know she had a sports dream. On Monday, Lani Teshima lived it out, at age 52.

She completed the Boston Marathon in 4 hours, 34 minutes, 56 seconds, tears covering her face the final few miles.

“I was unathletic. I was always the last one picked for anything in P.E.,” she said.

Right around the time she graduated from Pearl City High School in 1981, Teshima started running purely for fitness reasons.

“It gave me a way to exercise without joining a team,” she said.

But when she asked her ex-boyfriend, who was a member of the cross country team, if he thought she could complete the 26.2-mile marathon distance, he said yes — but only after a few years of preparation. That got her competitive juices flowing; determined to prove him wrong, she registered for the Honolulu Marathon which was less than six months away.

With no experience and no Internet in those days, she got training ideas from magazines like “Runner’s World.” That’s also where she discovered that elite competitors like Bill Rogers, Frank Shorter and Patti Catalano Dillon had run Honolulu.

“That was a big deal, that I could be in the same race they’d been in,” she said.

The first one was more to prove a point than anything.

“Then it became a running joke,” she said. “I’d do one every 10 years or so, usually after a milestone birthday. ‘Oh, I’m 30 and I’m out of shape, I better train and run a marathon.”

But the fitness was not consistent … both exercise and diet.

Teshima, who is 5-feet-21⁄2, weighed around 125 pounds when she ran her first marathon. As she got older, her weight fluctuated — but it went up a lot more than down.

“I refused to weigh myself when it was obvious I’d reached 200 (pounds),” she said.

Gastric sleeve surgery in 2012 reduced the size of her stomach and helped her lose 80 pounds. She said this relatively new procedure doesn’t have the potential negative side effects of gastric bypass surgery.

“Gastric sleeve does nothing but make your stomach smaller,” she said. “If you mind what you’re eating and how you’re eating you won’t get big again. There are people who don’t follow the doctor’s instructions and then wonder why their stomach is extended again.”

With smaller meals and more steady training, she steadily got healthier.

She also got faster, running 26.2-mile marathons in the time it used to take her to complete half marathons.

So much so that she qualified for Boston last May at the Mountains to Beach Marathon in Ventura, Calif., with a time of 3:54:48.

A friend, Vanessa Kline, helped push her to the finish line.

“She’d attempted to qualify in a race before that and didn’t qualify,” said Kline, who ran in the Boston Marathon in 2013. “But she’s very determined and this was two years in the making. We both cried at the finish.”

Running at Boston was more a celebration than a competition for Teshima.

“The culmination of a true journey of mind and body, running has changed my life,” she said. “It provides a personal journey but also a very large, very supportive community. All you need to get started is a decent pair of shoes and the willingness to go run around the block.”

And it doesn’t matter if you were the last pick in P.E.

Reach Dave Reardon at dreardon@staradvertiser.com or 529-4783. His blog is at Hawaiiwarriorworld.com/quick-reads.