UFC fighter Alan Belcher meets with Brazilian jiu jitsu legend Olavo Abreu. The third-degree black belt is the head instructor of Phuket Top Team, a fight gym on the eastern side of Soi Ta-iad.

Abreu greets Belcher with a hug. “I saw you knock out Rousimar Palhares in 2012,” he says. “Fucking amazing.” Palhares was a jiu jitsu fighter with a nasty habit of not letting go even when opponents tapped out. Belcher was the 2-to-1 underdog, but when the final bell sounded it was Belcher who prevailed.

“I trained to stay calm and find a way out of his holds,” says Belcher. “Breathing played a big part in that.”

We don’t normally associate fear with professional MMA fighters, but even the most ruthless among them suffer from the effects of panicked breathing, says trainer Steve Maxwell, a former jiu jitsu champion. It floods the body with stress hormones, reduces oxygen intake, accelerates time to fatigue, bottlenecks energy and increases muscle tension.

In short, such breathing sabotages your performance. The secret, Maxwell says, is to breathe through your nose, using your diaphragm to draw as much air as you can. That stimulates the vagus nerve, which calms your nervous system by counteracting the fight-or-flight response.

“Once you learn how to breathe and remain calm, you can begin to master all the other elements of your game,” says Abreu. “That’s the secret to becoming a champion – staying calm and putting it all together.”