Across North Texas, cross country races are under way - 19 this weekend alone.
Both boys and girls have been preparing for the races all summer but what they're training for is at the center of a big debate.
Varsity boys in district, regional, and state championship races run three miles under University Interscholastic League rules but the girls run only two miles.
Running can make you barren - that used to be the thinking, says Charlotte Lettis Richardson, producer of the documentary, "Run Like a Girl."
"There was a great fear 50 years ago that somehow women would damage themselves, their reproductive organs, that we might collapse," she said.
It was from that era that rules governing cross country races in Texas high schools were born.
Andrew Cook coaches the girls' cross country team at Flower Mound High School. He says only Texas and Oklahoma are holding on to the old two-mile rule for girls. "I think it's just silly, basically, we've got these old ideals. I think we're in the 21st century now."
"I think the guys kind of wish they could run faster and better than us, but it's all about training, and if you train hard enough, and you care about it enough, you're going to be able to do as much as you want to do," said Flower Mound runner Taylor Light.
The Cross Country Coaches Association of Texas has set up a Facebook page to push for the change.
But a Texas Girls Coaches Association poll found 68 percent of their cross country coaches opposed the girls racing further. Some of those coaches coach cross country in addition to other sports.
Executive Director Sam Tipton said: "They're afraid it's going to hurt participation... Our coaches tell us if we increase that, a girl who is running cross country, and not a specialist in cross country, is not going to look at that sport favorably."
Cook's runners laugh at the idea of another mile making a difference. Their UIL races may be two miles, but they train around 45 miles a week.
The UIL is expected to take up the issue at its next legislative meeting in October.