'Bachelorette' Star Ben Z Is A Bodybuilder Now

'Bachelorette' star Ben Z is more concerned about his rock hard bod than a follow-up run on "The Bachelor."

Ben surfaced this weekend in San Francisco where he competed in his first bodybuilding competition. He didn't win, but more importantly he didn't finish in last place ... ultimately coming in 8th out of 15.

Ben tells us he's 210 lbs now ... down 90 lbs from his days as a linebacker playing college football, which is when that "before" pic was taken. He claims he's leaned out naturally with diet and exercise -- sans steroids or testosterone boosters.

Many thought since he was last season's resident hardbodied badass ... he'd be a shoe-in for "The Bachelor." He tells us producers approached him but he didn't get back in time with his answer.

Spending too much time in the gym, Ben?