At the Silver Glove Boxing Championships, two of them, Kyle Lacanlale, 8, and Nikolai Mallot, 11, both won gold medals while Tim Minkel, 14, won silver in the championship, held last month at American Canyon Middle School.
Minkel, with just about six weeks of training, weighed in at 115 pounds; he defeated his first opponent and made it to the finals where he won a silver medal.
Lacanlale, who's been training for more than a year, competed in the 60-pound division. The San Ramon third-grader fought three rounds to take home the gold in the youngest division.
Mallot competed in the 75-pound division. He's been training five days a week for just six months. In what was his second amateur match, Mallot defeated a boxer who weighed in and competes two divisions above him.
In addition to winning his Silver Gloves debut, Mallot also won a championship belt as Best Fighter of the Night and Best Fight of the Night for all divisions, ages 8 to 25, taking home two trophies and one championship belt.
"I have never seen such true, raw talent at such a young age as I see in Nikolai," Rubio said. "I guarantee we will be seeing his name a lot more in the sport of boxing."
Silver Gloves is a national program for young men and women ages 8 to 18. Mallot and Lacanlale were eligible to move on in the Silver Gloves competition, but opted not to compete in regional matches.
"We're getting ready for the Junior Olympics next year," Rubio said.
All three young boxers had to convince their parents to left them get in the ring.
"I wanted to start when I was young but my mom and dad said no," said Mallot.
He was persistent enough to get his father to take him to a ring.
"My dad got tired of me asking to learn boxing," Mallot said, adding that finally, his father took him to a ring in Brentwood. "My dad said, 'Train him hard enough that he won't want to come back.'"
As soon as they were done, he asked when they could return, and they discovered Elite. Mallot said Rubio watches out for his boxers.
"Coach Paul won't just put you against someone. He'll put you against someone who's a good match," he said.
Although the three are anxious to fight, Rubio said a lot of opponents back out at the last minute. He said that's especially true for Mallot.
"They see him shadow box or work out on the bag -- it's a fear factor," he said. "They see how good he really is and they get scared."
Lacanlale admitted getting punched isn't fun.
"It's hard to get hit, especially when you're fighting someone bigger than you," he said.
But Rubio describes boxing as "safer than football,"
"It's one of the safest sports around. If a kid takes more than two head shots in a row, they give him a standing eight count," Rubio said. "The kids at this age don't have the strength. They haven't developed the power."
Under USA boxing, they're required to wear headgear, a mouthpiece and a cup. The fights are three rounds.
All three are dedicated to the sport, training five days a week and eager to slip on the gloves whenever they can.
Four days a week, the kids get basic boxing training. Rubio stands on the sidelines issuing specific instructions as they spar, for example.
Beyond that, they get strength and conditioning work to develop speed, agility and coordination. One day a week they do cardio work.
Rubio was a boxer himself. He was born with a birth defect, spina bifida, in which the bones of the spine do not form properly around the spinal cord, but with the encouragement of his father, he learned to fight to protect himself from bullies.
In 1998, Rubio climbed into the ring on a dare during a contest -- Battle of the Big Boys -- held by a Bay Area radio station. He knocked his opponent out in less than 30 seconds and a career was born.
He went undefeated until 2004, when he snapped two ligaments in his shoulder, both losing the fight and ending his career as a professional boxer.
Rubio spent time as a personal trainer and opened Elite in 2008. He knew he wanted to coach boxers, and began with professionals. That turned out to be a poor choice.
"They're harder to work with," he said, explaining that many of them had already developed habits that are difficult to break. "It's easier to mold them from nothing and create a good boxer."
Rubio also offers anti-bullying seminars, and has taken his message to local schools, including Mohr and Donlon elementary schools.
Although Rubio's gym is filled on any given night of the week with would-be boxers, the gym's youngest boxer, Lacanlale, said it's not for everyone.
"If you're a person that likes to get hit, this is the sport for you," he said.