Before Brian Viloria made the proverbial climb to the top of the mountain, he first had to conquer a physical climb.

On the way to becoming the IBF light-flyweight world champion, Viloria used the mountain trails near Oxnard, Calif., as a key element in his training program.

"It's all inclines, going up 500 feet, 600 feet," Viloria said. "Sometimes, you find yourself crawling."

There was a time when Viloria could not complete the one-hour run. Now, he can do it twice in one day.

"My conditioning in the ring is at a peak performance now," the Waipahu boxer said.

Coincidence or not, Viloria said he is in the best shape of his eight-year professional career. He won the IBF light-flyweight championship in April, and will defend it for the first time on Saturday.

Viloria (25-2 with 15 knockouts) is scheduled to face Mexico's Jesus Iribe (15-5-5, nine knockouts) in the main event of the "Island Assault" boxing card at the Blaisdell Center Arena.

The mountain runs are the brainchild of Robert Garcia, Viloria's head trainer at the La Colonia Boxing Club.

Viloria remembers a not-so-fond time in December 2007, when he first joined the La Colonia gym.

"The first time I did it, oh geez, I thought my lungs were going to collapse," Viloria said of his initial mountain run. "The inclines ... it wasn't just one. It was one after the other and we were doing it every other day."

There were other boxers from the La Colonia team who could not complete the run. In an effort to motivate them, Garcia gave them a warning.

"He said if you slow down, there are mountain lions over there that's going to be after your (butt)," Viloria said. "I haven't seen any, thank god."

Garcia said: "A year ago, Brian couldn't do it. A lot of guys can't do it. It's a tough run. But now he goes up to the top and comes back down and wants to go again. It's definitely helped his conditioning. We know we're ready to go 12 rounds every time."

In another drill designed to build Viloria's strength and stamina, Garcia likes to use bigger sparring partners.

Viloria is the IBF world champion in the 108-pound class. During the peak of his training last month, he sparred against boxers who were 125 to 130 pounds.

"He's going against all these bigger, stronger guys, so when he goes into the actual fight, his opponent's power is going to feel a lot lighter," Garcia said.

The same training regimen worked wonders in April, when Viloria knocked out Mexico's Ulises Solis in the 11th round to win the title.

"We did all the same things," Garcia said. "When he won the title, he was the stronger fighter in the late rounds, that's why he won. That's where all the training pays off."

It also helps that the La Colonia gym is isolated in Oxnard — a 2-hour drive from the bright lights of downtown Los Angeles. Viloria spent 10 weeks there preparing for Saturday's bout.

"For 2 1/2 months, it's nothing else but boxing on our minds," Viloria said.

There are also quality boxers to train with at La Colonia, including Steven Luevano, the WBO featherweight world champion. Garcia is a former world champion himself, the IBF junior lightweight title holder from 1998-99.

Perhaps most important, Viloria has maintained his humility as a world champion.

"A lot of fighters, when they win the title, they want to be the boss," Garcia said. "They want to say when they run, when they spar, when they train. With Brian, there is no problems. He trains with all the other guys on the same schedule — he doesn't put himself above them.

"When I tell him he has to do one more round, he does one more round. What makes Brian great is he doesn't just want to be the world champion. He wants to be the greatest junior flyweight in the world, and he's willing to work for it."