Not everyone can complete a 5-kilometer run without huffing and puffing in the end. For six-year-old Keelan Glass of Abilene, Texas, though, a 5K run is just a short stroll.

Compare that to the half-marathon that the young girl ran on Oct12. According to the Association of Road Racing Statisticians, Glass' time of 2:46.31 over 13.1 miles (roughly 21.08 kilometers) is a United States record for her age group. She is also the youngest runner to successfully complete a half-marathon, breaking the previous record held by a nine-year-old.

Keelan's mother Tracy, a doctor, inspired her daughter to take up running after a conversation over lunch. Dr Glass and her husband are both triathletes who have competed for charity. After consulting with pediatricians, Keelan signed up with a local running group, with proceeds from her races going to the charity Pregnancy Resources in Abilene. So far, she has raised $1,600.

She's not stopping yet -- the bubbly young lady thinks she can do a full marathon by the time she is ten, following in the footsteps of Indian marathoner Budhia Singh, who had competed in 48 marathons by the time he was four, and whose running story was told in the documentary "Marathon Boy."

However, just like in the case of Singh, some quarters are expressing concern over what seems to be too much wear and tear on the young woman's body.

“There’s a lot of potential for bad things and not a lot of potential for exceptionally good things to happen,” pediatrician William Moore of Dallas told The Dallas Morning News.

Even her mother is not yet convinced about her daughter's readiness.

“Just because she could, I’m not sure that’s a good reason to. Mom would have to do a lot more research before that happens," Tracy Glass told the Morning News.

That doesn't seem to faze Glass, who didn't even look gassed out after finishing half-marathon.

"God keeps me running," said Glass after she was asked what kept her going.

Watch the six-year-old's amazing journey HERE: LINK