NASHVILLE, Tenn. (WTVF) — Thousands will take off from Nashville's usually-bustling downtown Saturday for the St. Jude Rock 'n' Roll Marathon.

Among the crowd will be a father of a blended family of 15 kids. Now, that sort of juggling might be a lot for some, but for Dave Quint, not so much.

"Oh, juggling's not hard, it's rather natural," smiled Quint, juggling while he spoke. "I was a runner first before I was a juggler, and then I thought, 'the arm motions are exactly the same. I can do that.' Do anything long enough, eventually, you get good at it."

How did Quint become the marathon's running juggler? In his years at the Naval Academy, he got bored standing watch, so he juggled.

"Greetings!" Quint said, juggling outside the Music City Center as a trolley of tourists drove by. "Greetings, everybody! How y'all doing today? Enjoy Nashville!"

Quint believes when you have a talent, you use it for good. There's a reason he feels that way.

A brain tumor took the life of Quint's sister. He knew he needed to do something in her memory. He's been using the attention from his running and juggling to raise awareness and funds for St. Jude Children's Research Hospital. He's been doing this for years including when cancer hit that big family.

"Mira, our 17-year-old, she had thyroid cancer," Quint explained. "She had surgery right here at Vanderbilt. It's been about a year, and she's made a full recovery. I had no idea cancer would be so involved with my family."

The juggling hasn't always been easy. Over 23 years, Quint's gone through 12 surgeries, three of which were on his spine.

"Nine months ago, I couldn't get up off the floor," Quint said of the period just before his most recent surgery.

On doctor's orders, Quint's slowing down.

"It's actually somewhat agonizing, but I wanted to do it one more year," he said. "It's my final 5K running and juggling for St. Jude. I'll be walking in the future."

So, does Dave ever drop the things he's juggling? About once a mile, he said. But that's OK. When you have this important a mission, with a big family to back you, you pick up and go.