The very thing that made Ronda Rousey a superstar is going to be the same thing that hastens her retirement as a mixed martial arts fighter.

Rousey is not only one of the most successful and dominant fighters of her time but she’s almost without peer in the history of combat sports when it comes to promoting a fight.

UFC president Dana White announced on Oct. 12 that Rousey would challenge Amanda Nunes for the women’s bantamweight title in the main event of UFC 207 on Dec. 30 in Las Vegas.

The reaction, predictably, was over the top.

“[The announcement of] Ronda’s return garnered 489 million impressions, making it the most re-tweeted announcement in UFC history,” White said via text message to Yahoo Sports. ” … Her return is huge and yes, the PPV will be massive.”

There won’t be many more of them, if Rousey sticks to what she said during an appearance on “The Ellen Show” that will be broadcast on Tuesday.

“Not that long, I’m wrapping it up,” Rousey said when asked by host Ellen DeGeneres how much longer she planned to fight. “This is definitely one of my last fights. Everyone better watch, because the show isn’t going to be around forever.”

And then Rousey, 29, went on to explain that the incredible demands placed upon her are what have worn her down.

Ronda Rousey says UFC 207 will be one of her last fights. (Getty Images) More

Rousey-Mania exploded in 2015 and she’s rarely gotten a break since. She’s become an actress, and that has brought on another dimension of interest and pressure. She’s a swimsuit model who earlier this year landed the cover of the Sports Illustrated swimsuit issue. She’s a best-selling author, and needed to do a book tour to promote that. She’s a product endorser and has appeared in various ad campaigns.

And those are just her side jobs.

In August, before her fight with Nunes was announced, White predicted that whenever she did return to competition, it would be a mega-event.

“Ronda will be the biggest pay-per-view in our history and it will be the record for a long time,” White said in August. “It is all the mainstream media will talk about all over the world. When we announce that fight, they will be tripping over themselves to get to her.”

All of it has left her in one tiny fishbowl in which the sides seem to be closing in. The interview with DeGeneres is the first she’s done this year, and she’s declined requests submitted to UFC public relations for interviews since the Nunes fight was announced.

She told DeGeneres that it has gotten wearying, at a minimum.

“The build-up is more tiring than anything else,” she said. “If we had a fight right now, I’d be like, ‘I’ll fight right now,’ and then I’d go get dinner and I wouldn’t really be tired about it. It’s the weeks and weeks of build-up beforehand and you know you’re fighting this one person and it’s your showdown and the most important thing in your whole life and millions of people are watching.

“It’s that build-up for weeks on end. If it happened right now, I wouldn’t be nervous at all. It’s the waiting.”

Rousey got through her first 15 mixed martial arts fights – three amateur and 12 professional – with very little damage. Of course, it’s hard to take much damage when you win your fights in 34, 14 and 16 seconds, as Rousey did her three bouts prior to fighting Holly Holm at UFC 193 last year.

But she was battered by Holm in arguably the biggest upset in MMA history. Only seconds into the fight, Rousey was cracked in the face by a forearm from Holm that seemed to leave her woozy for the remainder of the bout.

The vast majority of great fighters throughout history have had that one fight, or a small handful of fights, in which they took far more punishment than they’d ever done previously.

The late, great Muhammad Ali was battered by Joe Frazier in two of their three bouts, and said his win over Frazier in Manila in 1975 was the closest thing to death he’d ever experienced. Ken Norton broke Ali’s jaw in a 1973 match.

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