Claressa Shields is a force to be reckoned with.


At 26 years old, Shields is a powerhouse inside the boxing ring as the first undisputed champion in two different weight classes during the four-belt era.


Now ready for a new challenge, she's making her mark in mixed martial arts.


The two-time Olympic gold medalist has signed with the Professional Fighters League, a change in her career that she said was borne out of her experience during the past year of the coronavirus pandemic.


"Going through the pandemic, it was a depressing time," Shields told Michael Strahan in an interview that aired Tuesday on "Good Morning America." "I wasn't in the ring. I had gained a whole bunch of weight and I'm like, 'I've accomplished everything in boxing.'"