12-Year-Old Girl Arm Wrestler Takes on Michael Strahan on 'GMA'

— -- Grace Houston is a 12-year-old arm wrestling phenomenon.

She started arm wrestling three years ago after expressing interest in the sport to her father, who is himself an avid arm wrestler.

Houston, the Minnesota State Kids Division Arm Wrestling champion, appeared on “Good Morning America” today to talk about her success. She said her father trained her, and the first thing he taught her was how not to break her arm.

Houston said she’s challenged by boys and girls at school all the time. If she beats them, they make excuses, she said.

"Sometimes they say, 'I wasn’t ready,'" she said on "GMA."

Houston said people seem surprised by her strength.

"I’m really small and I don’t look that muscular, but I am actually pretty strong," she said.

She is so strong that mixed martial artist and UFC Women’s Bantamweight champion Ronda Rousey took notice and had a special message for Grace today. In a video message that aired on “GMA,” Rousey congratulated Grace, saying: “I just heard about all of your success in the arm wrestling realm and I just wanted to say congratulations on all your success and continued success. Keep showing those boys and girls what's up!"

Houston said the message was "amazing." She also took on Michael Strahan of “GMA” in a morning show arm wrestling battle -- which she won.