A bunch of four- and five-year-old boys are lined up in front of the mirror at American Karate in Monterey, stretching, doing mini pushups, bragging about their punches as they throw them at their reflection, while their parents watch from folding chairs at the side of the room.

To the front of them stands instructor Matt Durney, watching with a serious, almost stern expression on his face.

“Mr. Durney, someone left their underwear in the bathroom,” calls out a little boy as he runs to join the class.

Durney doesn’t reply, but tells the class to line up.

“Ready to go?” he asks. “No talking, and hold still.”

“Yes sir,” the boys call out.

“How is everyone today?” he asks. “Now bow in.” The boys turn and face the American flag at the back of the room, and completely not in unison, bow.

The boys turn back to face the mirrors, bow again, then Durney instructs them to do jumping jacks while he counts. The boys are all bouncing to their own drummers, as Durney tells them to stop, and watch him for a minute.

“You need to count as your hands slap your sides,” he says.

The kids do a bit better on the next round, then start squats and punches.

“Everyone ki hap,” Durney says, and the boys give their best warrior cries as they punch.

“Now choon bee!” Durney commands, and the boys return to ready position, some of them remembering to keep their clenched fists up to guard their bodies.

An older kid at the back of the room is climbing on the torso of a rubber dummy, giving the rubber man head butts and kneeing him in the chin.

The little boys are now running laps around the class, jumping over a blue Styrofoam noodle that Durney holds out for them. Two of the kids are roughhousing as they run. Durney is right on them.

“No fighting,” Durney says. “It’s not funny. You can get into big trouble.”

The boys immediately stop, and the class lines up again.

“Raise your hand if you want to get a gold belt or a black belt,” Durney says. All nine hands shoot up.

“Okay, you guys know what you’ve got to do then,” he says. “You’ve got to focus and pay attention. Remember, part of your karate training is also following directions.”

Durney fluidly demonstrates a series of kicks, and the boys follow. Then he leads into splits. Only Durney and one four-year-old boy can do them.

The class ends with forward rolls and kicking at targets, followed by pushups.

“Let me ask you guys, should you go around using karate on people?” Durney asks.

“No sir!” the boys reply.

“That’s right, the only time you use it is if someone attacks you, that’s why I teach you blocks,” Durney says. “The most important thing you can learn now is self-control and self-discipline.” The boys face the flags and bow again, then bow to their instructor.

Then Durney gives them all high-fives before they run off to their parents, with just a little bit less boy energy bottled up.