Mixed martial arts, the rough-and-tumble fighting form more commonly known as “MMA,” has surged in popularity with children. An estimated 3 million children under the age of 13 are now taking MMA classes around the country, according to Orlando, Fla.'s WKMG.

The sport, which has enjoyed massive mainstream popularity through leagues like theUltimate Fighting Championship, and the 2011 Oscar-nominated film "Warrior," is reportedly now being studied by children as young as 5.

"The trend I've seen with children and mixed martial arts is an explosion," Jonathan Burke, the owner of the VI Levels, a mixed martial arts gym in Ocoee, Fla., told WKMG.

However, Burke says his goal is not to turn the kids into street fighters, but rather to help them get into shape and deal with issues ranging from bullying to mental illness. "We use it to teach these kids self-defense and how to deal with mental issues," he said. "It's not about fighting. It's about getting in great physical shape, improving your mental focus and discipline.

"I can't guarantee they won't be a bully,” Burke added, “But I can guarantee that the way we present the information, we're going to make bullying look so bad, they're going to be ashamed to be associated with that word.”

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