Ronda Rousey: I am full of fear, that's why I work hard

Bantamweight world champion Ronda Rousey isn't just undefeated in MMA competition. The UFC superstar also says that she wouldn't ever consider tapping out, or submitting, to an opponent -- even if it meant serious injury or possible death. 

"No," she recently told Australian outlet ABC, ahead of her UFC 193 main event in Melbourne, Saturday.

"Once I got caught in a neck crank, in my first UFC fight. And it was in that moment that I had to make that decision. Possibly if I didn't tap out, I could hurt my neck, I could be a quadriplegic. Anybody else, anyone sane, would have tapped out."

She is talking about her title defense against Liz Carmouche. Though she defeated the challenger in less than a round, Rousey had her back taken and was in big trouble in the opening moments of the fight. Carmouche could not get under the champ's chin to finish a rear-naked choke, but she did lock on nasty neck crank -- or cervical lock -- whose logical conclusion is the breaking of a neck.

Despite the pain, Ronda pushed through and refused to concede. "In that moment, it mattered too much to me," she explained.

"It didn't even cross my mind to give up."

Despite her feats, Rousey is no superhero. She still deals with fear.

Bravery, after all, is action in spite of fear, not the absence of the emotion. "Scared? Yeah, I mean I'm full of fear," she admitted.

"Without any doubt. I'm so afraid of failure that I work harder than any of these girls possibly could."

Her fighting philosophy extends far beyond the cage, of course. In fact, martial arts taught the two-time judo Olympian much of what she's had to use in her general life.

"There's a lot of meaning to the word fight. It doesn't just mean two people trying to hit each other. It can be applied to anything. And that's why it's a metaphor for life," she went on.

"Everything I've learned from fighting, I've been able to apply to my life outside of it. The main lesson I get from it, it taught me to be brave, and it taught me to value myself."