Ronda Rousey -- SHE'S GOTTA HAVE IT! Down for Pre-Fight Sex

Ronda Rousey ain't ashamed to say it ... she's all about banging dudes before she steps into the octagon -- thereby cementing her place as the coolest chick in sports.

The MMA champ revealed her pre-fight sex rituals with Jim Rome on Showtime ... saying, "I try to have as much sex as possible before I fight, actually."

Rousey says the old theory about no sex before fights doesn't apply to female fighters because making the beast with two backs increases testosterone levels in women -- clearly a plus before brawling.

TMZ broke the story ... Ronda is jumping to the UFC to become the league's first female fighter.