With their plodding routines of protein-packed dieting, lifting and down-to-the-minute scheduling, bodybuilders have a reputation for being a bit dull. They’re like monks—insanely bulked-up, shredded monks—on a monomaniacal quest for physical nirvana.

Kali Muscle, 39, shatters convention. The Oakland-born athlete, whom many may recognize from the “happier than a bodybuilder directing traffic” Geico ad, went from college footballer, to San Quentin convict, to philosopher and author. It’s a biography, laid out in his new book From Xcon to Icon, as intriguing as his personality, which comes through in thundering rants and fitness-related pep talks he shares to his tens of millions of viewers on YouTube.

“People have connected with my story,” says Kali, who comes to San Jose this weekend for TheFitExpo to promote his new book.

Kali, born Chuck Kirkendall, grew up in a bullet-riddled Oakland neighborhood, where he says he was forced to pack heat as early as elementary school to protect himself. As a teenager, he found solace in the gym and became an accomplished runner and wrestler. He landed a football scholarship at Fresno State.

In college, things started to fall apart after the death of his older brother. Coping with trauma and dead broke, he resorted to robbery and wound up in prison.

On a steady diet of canned tuna, Top Ramen and endless weightlifting, the ex-college football star developed a Herculean physique. In 1997, when California prison banned weightlifting because inmates were getting too strong, Kali had to get creative.

On leg days, he’d have guys sit on his shoulder for weighted squats. For chest presses, he’d have someone lean in with their body weight for resistance. For weights, he’d use trash bags and water bottles.

After seven years, Kali got out and fell back into the street life, as a dope dealer and pimp, which earned him a few more stints behind bars. Only after his final release in 2009 did he discover bodybuilding, started competing—and winning. A 2010 acting gig in a Matthew McConaughey-directed country music video quickly led to casting in national commercials for Snickers, Old Navy, Comcast, Honda and, this summer, a soon-to-air TV show.

Armed with more than a decade’s worth of innovative inmate exercise routines, Kali began posting his prison-style bodybuilding workouts online and quickly garnered a following.

“I’m not saying being in prison was worthwhile,” says Kali, who brings his message of overcoming the odds to juvenile detention centers, jails and prisons. “It was a complete waste of time. But it has made me appreciate my freedom. Yeah, I’m labeled an ex-con, but that doesn’t mean I can’t be successful.”