18-year-old Kayla Montgomery is one of the best runners in the country. She also suffers from multiple sclerosis. Those two facts are not unrelated.

The New York Times detailed the surprising rise of Montgomery, who has turned the seemingly debilitating disease into an athletic advantage. MS is a degenerative disease that blocks some of the nerve endings connecting Montgomery's legs to her brain, particularly when exercising, and so she loses feeling in her legs when she's running at top speeds. That means that her legs don't feel tired — in fact, they don't feel anything — during races, and she can maintain a sprint in cruise control all the way to the finish line.

That's a huge advantage over her competition in the 1,600-meter, 3,200-meter, and 5k races. Her competitors will certainly slow down as their legs begin to move more slowly and get tired. But Montgomery doesn't feel that tiring, and so she can barrel through the entire race without slowing. She had been the worst racer on her team before her diagnosis three years ago. But once she recognized her legs' numbness, she began to take advantage. Her 5k time quickly improved from 24:29 to 17:22, an unheard-of cutdown among runners. 

Kayla Montgomery talking to The Winston-Salem Journal.

But any disruption in her running pace makes those numb legs fall, and Montgomery collapses to the track at the end of each race. “I start out feeling normal and then my legs gradually go numb," she told The Times. "I’ve trained myself to think about other things while I race, to get through. But when I break the motion, I can’t control them and I fall.” She typically has a coach or assistant catch her and keep her from faceplanting. It doesn't always go successfully.

Montgomery's story is a fascinating look at how a medical issue can become an advantage in sports. She's part of a long line of athletes to take advantage of so-called maladies. The best comparison is to basketball or volleyball players with Marfan Syndrome, a genetic disorder that makes people taller, with longer arms and fingers. That length is great for those sports, but Marfan's can also lead to early death if left untreated. Flo Hyman, considered America's best women's volleyball player ever, suddenly died in 1984 due to a ruptured aorta caused by Marfan Syndrome. Her Marfan-aided 6-foot-5 height helped her rise to the top, but also caused her end. Likewise, don't expect runners to be praying for MS. “I think there’s a benefit to numbness,” her coach told The Times. “I don’t know anyone in their right mind, though, who would trade this; who would say, ‘Give me M.S. so I have a little bit of numbness after Mile 2.’ But I think that’s when she gets her strength.”

Is that an unfair advantage? That's a question the Olympic committee had to address when it decided to allow the bladed Oscar Pistorius — now known more for his trial for allegedly murdering his girlfriend — to compete alongside traditional athletes. Montgomery, the North Carolina state champion in the 3,200, will hold on to her title as long as she can.

(Top image: lzf via Shutterstock)