After coaching her daughter's youth soccer team through two undefeated, largely unchallenged seasons, Jenny Mackenzie came up with a rather novel idea.

Instead of continuing to dominate other girls their age (8-9) and older, how about giving her Mighty Cheetahs more of a challenge by putting them in the boys' division?

Not everyone enthusiastically jumped on board at first.

"There was a little bit of resistance, actually, from some of the parents of the Cheetahs," Mackenzie said in an interview with the Deseret News. "There were comments, like, 'Well, Jennie, what's the matter with the girls continuing to win?' "

And one mom even questioned whether the girls were in danger of physical injury.

But the Mighty Cheetahs took the field against the boys — and the results are chronicled in the thoroughly charming short film "Kick Like a Girl," which debuts tonight at 7 on HBO.

"Kick" is not an ersatz "Rocky." It's not so much about winning and losing as it is about teamwork and taking on challenges.

Challenges like the one faced by Mackenzie's wonderfully articulate, enthusiastic daughter, Lizzie, who won't let diabetes stand in her way.

"Kick Like a Girl" is also a gentle look at how gender roles are stereotyped — and how parents have trouble looking past them.

Let's just say that some parents had a hard time watching their boys lose to girls.

"There definitely were some parents and some families who felt pretty strongly," said Mackenzie. Including one opposing coach who didn't want to be interviewed for the film.

"He was very — let's see, what's the right word? I think he had a lot of ambivalent feelings about us participating in the boys' division," Mackenzie said with a laugh.

On the other hand, the boys themselves seemed to handle things quite well.

"Absolutely," Mackenzie said. "And I think, for me, the boys are really quite heroic in the film. I just find them so authentic, so honest, so funny.

"I think if you consider gender and gender issues and you leave it up to the kids, they figure it out. It's really us parents who have to constantly remind ourselves and keep ourselves in check for the way in which we socialize kids. And the way in which we gender stereotype."

While some of the parents have a lot of trouble wrapping their heads around the fact that the girls team might actually be better than some of the boys teams, the boys themselves could more easily admit that were outplayed.

"If one of my friends say, 'You kick like a girl,' I'd be, like, 'Yeah, that's nice. Thank you,' " one of the boys says in the film.