Say you're almost 78-years-old, retired for more than 20-years, and have plenty of time to do whatever you want.

What would you do? Travel? Hobbies? How about run a marathon?

That's exactly what Bobby Crim, the founder of Flint's premiere road race is doing for the first time.

Bobby Crim tells NBC25 in an exclusive interview, "They've always told me, the better shape you're in physically, the sharper you are mentally, and I need all the help i can get."

There's a lot of feet to those words...strides actually.

In a few weeks, Bobby Crim turns 78-years-old, but he's not slowing down.

He's run 20 races since April.

"I did a half marathon about 4 weeks ago, half marathon 3 weeks ago, and I did one last February. I kind of like them," says Crim.

A half marathon is 13.1 miles. Crim can do it in around two hours.

The marathon is double that, 26.2 miles.

Crim says, he never had the time to train for one until now.

"It's kind of like my bucket list. I've done my bungee jump, parasailing, the sky diving, but I got to do Boston."

To qualify for the Boston Marathon, Crim must complete another marathon in 4 hours and 45 minutes.

He's running the Gasparilla Distance Classic in Tampa, Florida this February.

He doesn't run for the finish line alone.

"The better feeling is knowing how good you feel as a result and that quality of life is extremely important to me. I want everyone to know, you don't have to give it up just because you're 50, 60, 70 years old."

It's what Crim sees himself doing when it's his time to go.

"I'd like to be about 105 or 110 and get hit by a meteorite while I'm out doing a good run. You go quick, but you enjoy it right to the end," Crim says with a smile.

NBC25 will follow-up to see how Crim does in his first marathon.

On another note, Crim says, the Crim Foundation has become something bigger than he could have ever imagined.

A few years ago, it was voted the best youth program in the country. Nike was #2.

The Crim Adult Training Program is the largest in the country with more than 1,500 participants.

This year, Bobby Crim was given an honorary doctorate of law from the University of Michigan.