(ABC News) -- Reinhardt Harrison began running shortly after he learned how to walk, so it didn’t surprise his parents when he began begging them to let him run a half marathon.
“I said, ‘No, no, you’re not ready,’ and he said, ‘Well, when can I?’” Reinhardt’s father, Dennis Harrison, told ABC News. “Running is his passion.”
Thinking it was a long way off, Harrison told Reinhardt that he could run the 13.1-mile distance when he was 10 years old.
Last week, Harrison, a volunteer youth running coach based in Falls Church, Virginia, had to make good on that promise by letting Reinhardt run the Alexandria Running Festival half marathon in Virginia.
Reinhardt set a new world record for the fastest half marathon run by a 10-year-old, 1:35:02, about 2 minutes faster than the previous record, and he wasn’t even running at top speed because his dad insisted he treat it as a training run.
“He’s actually beating me now,” Harrison, 54, told ABC News. “I keep telling him I still got a few more years. I might be able to get faster. Age is not on my side.”
But Harrison has received the occasional earful from parents and critics who say children shouldn’t run long distances at all. He said it isn’t for everyone, but Reinhardt likes it so much and has been training so gradually for the past seven years that an occasional long race is safe.
Dr. Alex Diamond, a sports medicine expert at Vanderbilt University in Nashville, Tennessee, said attitudes have changed over the years regarding children and distance races.
“Ten or 15 years ago, I think the answer you would have gotten from most of us is no,” Diamond told ABC News. “The trend has definitely shifted to, in a select few, it’s probably OK to do that.”
He said there isn’t scientific evidence to say whether children should or shouldn’t run long distances.
“In a normal, healthy kid with no injuries, there’s nothing we know of right now that says participating in these events would lead to growth plate or other injuries,” Diamond said.
To avoid over-training and burnout, Diamond said increasing distance gradually is a good idea. And making sure the child is self-motivated rather than pushed by parents or a coach is extremely important, he said.
“It sounds like the family really did handle this very nicely,” Diamond said of the Harrisons. “This is a highly motivated, unique kid.”