Boxer Holly Holm (3-0) is downsizing her gloves.

The 31-year-old former boxing champion on Tuesday announced she is retiring from the squared circle to pursue MMA full-time.

Holm (32-2-3 boxing) said she'll call it quits after her next boxing match, which is set for May 11 in Albuquerque, N.M. She fights Mary McGee (20-1).

A pupil of famed trainer Mike Winkeljohn at Jackson-Winkeljohn MMA in Albuquerque, Holm made her MMA debut in March 2011. She won by second-round TKO due to leg kicks. Two months ago, she made her big-show debut and earned a second-round TKO on the preliminary card of Bellator 91.

"When we were deciding which way to go with my future, my trainer Mike said it best: 'You want to climb a new mountain,'" Holm said at a press conference in support of her May 11 fight. "This thing has created a new spark in me, and I'm following my heart."

Holm, who also has kickboxed professionally, has ended all three of her pro MMA fights with body shots or leg kicks.

As a boxer, Holm has earned a 32-2-3 record with nine knockouts. This past June, she won the WBF, IBA Female and WBAN welterweight titles by avenging a vicious knockout loss to Anne Sophie Mathis.

Twice Holm has been named Female Fighter of the Year by The Ring magazine.

During her announcement, Holm also addressed a matchup with rival and multi-title champ Cecilia Braekhus that's been mired in squabbles between their respective promoters.

"I wish much success to Cecilia, but not fighting her does not, by any means, define my boxing career," Holm said. "I know there's a lot of talk about that, but what does that say about all the women I've already fought? I've never been a paper champion. I've grown so much every step of the way.

"I'm in this fight ... 100 percent. I'm not distracted. This is obviously an emotional, spiritual and physical journey, and I'm so grateful for the people who have supported me. I just want to fight where my passion is. I train in an MMA gym and always have."