Yahoo Sports 
The Welsch sisters, 10 and 12, are controversial endurance all stars
Kaytlynn Welsch is 12 years old. Her sister, Heather, is 10. They are both very, very fast, and they like to run very long distances. That in itself is enough to send many fellow endurance athletes into a lather.
As it turns out, a number of people are very upset that the Welsch sisters are allowed to compete in endurance events, for fear that doing so is damaging their young bodies and their prospects for future success. As reported in this terrific feature by the New York Times, the Welsch sisters combined have competed in more than 160 endurance races in less than two years. At the same time, the sisters have maintained high grades in school, with both seventh-grader Kaytlynn and fifth-grader Heather required to keep at least a 93 average in all subjects to continue their racing pursuits.
Continuing racing is certainly something the Alvin, Texas, natives want to do, and winning has become almost as much a part of their routine as lining up at the starting line. In August, Kaytlynn won the women's division of a grueling 13-mile XTerra cross country race in Waco, Texas. Her sister finished third.
Those honors were the start of an athletic controversy that has festered ever since, with detractors finding fault with the Welsch parents for pushing their daughters to complete daunting events at such a young age. Both sisters have excelled in triathlons, distance bike rides and particularly in long running events, where they both prefer trail races because of the variety in the scenery. In the months since winning in Waco, Kaytlynn also completed the Houston Marathon, her first 26.2-mile pursuit.
For Kaytlynn, running provides more than fitness in a form that is seemingly more safe for a 4-foot-7 middle schooler than a contact sport like soccer or basketball.
"For some reason, running is really fun, even though it hurts sometimes," Kaytlynn told the Times. "I enjoy it. I can go on and on without getting tired. It makes a purpose in my life."
Still, many runners have expressed concern about the Welsch sisters' long-term health, even if their personal doctors have yet to sound any alarm about their endurance participation. Other doctors have also given the sisters' participation approval, even if it is a more tepid variety.
"In general, kids should stick to kids distances and then race at adult distances when they are adults," Dr. Douglas Hiller, who has been the chief medical officer for the triathlon at the Olympics, told the Times. "[The distances run by the Welsches] sounds excessive. But if these kids feel it's a mission to do this and they aren't having adverse effects, I guess it's OK."
If they stay healthy, the sky could be the limit for both sisters, provided they remain interested in endurance sports. So far their parents claim that the girls can quit whenever they want, though there would be some concern about Kaytlynn walking away for fear of wasting a fantastic talent, as her father, Rodney Welsch, told the Times.
If the girls wanted to quit, "that'd be O.K.," Niki Welsch said without hesitation.
Rodney did not seem so sure. "Kaytlynn has too much talent to quit," he said. Besides, the girls say one thing one day and another thing the next.
"Kaytlynn said she wanted to quit the triathlon, and I said, 'You're not quitting, you need to stay with it,' " Rodney recalled. "Two months later, after she gets a new bike, she says, 'I love the triathlon now.' "
Want more on the best stories in high school sports? Visit RivalsHigh or connect with Prep Rally on Facebook and follow us on Twitter.
More sports news from the Yahoo! Sports Minute:
Other popular content on the Yahoo! network:
• Imposter's elaborate prep football identity scam
• Fourteen-year-old golfer changes face of the Masters
• Y! News: Dog owners re-create photos with their pets years later
