More than 45,000 runners from all over the world are set to converge on the big apple for the 2013 New York City Marathon this Sunday. Among them is Dave Obelkevich, a 70-year-old retired music teacher who has finished every New York City Marathon since 1976.

Obelkevich is in an exclusive group. There’s only around 400 people known to have completed 15 or more New York City Marathons, and he holds the record for most Marathons completed in a row, Sarah Huvane of the New York Road Runners -- which organizes the race -- told Reuters.

The Manhattan-based Obelkevich says he got inspired to take part in the 26.2-mile (42.1 km) Marathon after seeing a group of runners on a morning talk show in 1972.

“Back then it was four loops around Central Park," he said. "I don't think I did any races before I watched that program.”

Obelkevich’s first race took place in 1973. He finished the Marathon in 1974 but had to drop out due to dizziness in 1975. Beginning in 1976, he has completed every New York City Marathon, with the exception of the 2012 event, which was cancelled because of Hurricane Sandy.

According to Reuters, Obelkevich’s first finish was four hours, 20 minutes. He improved every year through 1982, when he accomplished his best time of two hours, 40 minutes. After that, his finish time decreased over the years to the point where he now finishes under five hours.

"In my 30s I thought if I can't run faster than the year before there's no point in finishing it," he said. "Now I just want to finish. That's my goal."

As Reuters reports, Obelkevich -- who has also ran marathons in South Africa, Japan, Switzerland and London -- prepares for the New York City Marathon by running 35 to 40 miles a week. He also does a long run once or twice a month.

Dr. Walter Thompson, a professor of kinesiology at the American College of Sports Medicine, told Reuters that Obelkevich is an example of what one can physically achieve at an advanced age.

"He's been doing it for a long time. He knows how to train," said Thompson, "but he's so atypical (of people in his age group), probably less than 1/10th of 1 percent."

Amazingly, Obelkevich told Reuters he is 10 to 15 pounds (4.5 to 6.8 kg) lighter than his high school weight. He says it’s all thanks to his running regimen.

"You can run at any age," said Obelkevich. "I'm never going to break a world record at age 70, so I run the race for fun."

The 26.2-mile New York City Marathon is set for Sunday, Nov. 3. Click here for more information about the race, and check out a video of Obelkevich's story below.