WEST PALM BEACH, Fla. - Children, as young as four are learning the core of mixed martial arts fighting.
It's a growing trend around the country, as videos spring up online of children punching and kicking one another.
In South Florida, they don't go quite as far with it, and parents are seeing huge benefits.
"I'd say it's not that violent, it's just fun," said Becky Slominiski, a 4th grader taking a class at American Top Team gym on Okeechobee Blvd.
It's technically called "Brazilian Jujitsu," and the sensei says the holds, pins and takedowns make up the core of mixed martial arts.
Elsewhere in America - especially the southwest - there are kids competing in bouts that include punching and kicking, similar to adult mixed martial art bouts that draw massive cable ratings.
"The only similarity here is the techniques on the ground, without the punching and the aggression," said Sensei Marcos DaMatta, a top black belt in Florida.
DaMatta says his MMA-style-fighting for kids courses grew as UFC bouts gained exposure.
He says it's never too early to teach kids the lessons mixed martial arts teaches, without punching and kicking.
"For kids it's not even about fighting, it's about confidence, and about defending themselves, and about avoiding fights."
Doctors say parents should closely watch children who step onto the mat. Young bones aren't fully formed and head injuries can be more severe.
"Before you start a regimen like that, have a psychological evaluation of the child, as well as an orthopedic evaluation," said Dr. Jaime Marchand, a pediatric ER doctor at St. Mary's Medical Center.
But parents say the impact of Brazilian Jujitsu is clear: for all the takedowns and competitiveness, the more kids do it, the more calm they become.
"One of the things I was concerned about was they're going to be more prone to fighting or violence, or trying to show what they know. It's been the opposite. They're confident, they don't have to get into any power struggle," said Carol Slominiski, Becky's mother.
Parents say they've never seen an injury during Brazilian Jujitsu, and say they would definitely draw the line if their kids were being pushed to compete in bouts, which are illegal in Florida.