Ronda Rousey
Ronda Rousey claims she works harder than Dwayne "The Rock" Johnson in the gym. Reuters/Jayne Kamin-Oncea/USA Today Sports

With her recent transiton to movies, Ronda Rousey -- the undefeated women’s champion in mixed martial arts -- has become the female version of wrestler-turned-actor Dwayne “The Rock" Johnson, says Bruce Buffer, ring announcer for Ultimate Fighting Championship (UFC). "With what she does in fighting, in what she does in movies, to what she does with her book writing, and her training, there is a similarity, here. Ronda is like a female version of The Rock...It's just exciting to see someone as a role model, herself, make this happen," Buffer told Fox Sports.

So far, this has been a banner year for the female judoka, with her appearances in the films “Fast & Furious 8” and “Entourage: The Movie,” a record-setting title defense victory over Cat Zingano in February and the release of her best-selling autobiography, “My Fight/Your Fight.” It is no small wonder that Rousey recently shared that she finds it hard to find time for romance.

Rousey also never wavers in her commitment to the UFC, with her next fight slated for Aug. 1 in Rio de Janiero against undefeated Brazilian fighter Bethe Corriea.

Buffer’s comparison of Rousey to Johnson is spot-on considering that the part-time WWE talent has continued to balance his Hollywood stardom with the demands of his wrestling fan base. The star of “San Andreas” puts in the effort to appear in select pay-per-view events of Vince McMahon’s company. His most recent appearance came during Wrestlemania 31, where he teamed up with Rousey to taunt Triple H and Stephanie McMahon.

Since then, the pair developed a bond that was exemplified by Rousey's revelation a few days ago that she is in a competitive gym battle with “The Rock.” The health-conscious personalities are constantly trying to one-up each other by registering more gym time and translating the effort to an impressive physique.