The 37-year-old is rarely without a red Gatorade and look of determination on his face.
He's got a black belt in karate, too, and isn't afraid to tell you that's why he's at the gym -- training to become a better fighter.
He's affable. Social. Hardworking.
Oh yeah, and he has Down Syndrome.
Alex has never let his disability hold him back nor define him. Instead, he's using it to get further and help others do the same.
"I'm a role model," he said proudly after a routine training session last Thursday.
“I want other people to see me doing this and they also get off the couch. I feel like a normal person.”
Alex's father, George Rivera of Hackensack, has always been a proponent of exercise and healthy living.
"It would have been very easy to give him a soda and let him watch TV all day," said the elder Rivera, 74.
"He knows he has to be a role model for other people, especially for other parents raising kids like him."
I'm a role model
Rivera has been exercising with Alex for as long as he can remember. He stressed the importance of enjoying exercise, which is why he signed Alex up for karate when he expressed an interest nearly two decades ago.
"I could care less about what level he is," the elder Rivera said.
"What's important is that he stays active."
His progression was slow and steady, and Alex only seemed to get better the longer he worked at the martial art.
Eventually, he earned his black belt and is happy to demonstrate a karate move.
Alex, who lives in an Englewood group home, says his motive for working out is to become a stronger fighter.
He works out twice a week with trainer J.C. Merino, who has him doing strength and cardio circuits with an emphasis on upper body strength.
"He always gives it his all," Merino said as Alex slammed a medicine ball and battle ropes nearby, moving swiftly from station to station. "He makes sure he gets it done."
Play a Michael Jackson song and Alex becomes a force to be reckoned with.
Working out keeps Rivera physically and mentally fit, his father said.
Most importantly, it provides him with structure, discipline and confidence.
"It changed my life forever," Rivera said. "I feel like I'm doing something with my life."
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