The age-old debate continues! Who’s tougher—a boxer or a mixed martial artist? Fans love to argue, fighters love to flex, and the internet never takes a day off. But two-time Olympic gold medalist Claressa Shields has actually walked the walk in both rings—and found success in each. Still, after getting a taste of MMA, the 30-year-old seems to have gained a whole new level of respect for the sport. Her honesty didn’t go unnoticed, earning a one-word reaction from none other than the king of cage swagger himself—Conor McGregor!

Rewinding a bit, Claressa Shields signed with PFL back in November 2020 to make her debut in the PFL (Professional Fighters League), and in June 2021, she fought Brittney Elkin, winning the fight via 3rd-round knockout. In October of the same year, she took on Abigail Montes, recording her first loss via split decision. However, she didn’t give up and pursued a third fight against Kelsey DeSantis in February 2024. If the gap in her MMA resume didn’t give it away, the toll of the sport was starting to take over.

Fast forward to May 2025, she appeared on the MMA Hour with Ariel Helwani, where she officially announced that her MMA career had come to a screeching halt due to the demanding nature of the sport. She reiterated this sentiment during her appearance in Gil’s Arena podcast, where she claimed, “PFL was fun. I proved a bunch of haters wrong. They [were] all talking about [how] some boxers can’t do MMA. And I went over there and I kicked those girls’ a**es.”

When asked about how training for MMA and boxing differed, Shields was quick to explain, “Come on now. MMA is way harder, maybe because I [have] done boxing my entire life, but MMA was different.” She further added that training for each MMA fight took her six months, and included practicing a plethora of areas, including “taken down… avoid take down… arm bars… chokes.” Later in the interview, she added, “I think you have to be crazy to do it,” but seemed proud of herself for having done it.

A clip of this interview was shared on Instagram, attracting hundreds of fans, and former UFC champion Conor McGregor was one of them, who commented, “CERTIFIED.” Even former UFC champion Tyron Woodley joined the conversation, writing, “Savage.” Among others from the MMA world, Angela ‘Overkill’ Hill reacted by writing, “She gets all the respect from us MMA folk cause she’s the only one at her level that tried! Would love to see her in Muay Thai.”

Shields herself reacted to the interview, writing, “SMOKE 💨 IN UNISON 😂.” Nonetheless, McGregor has always supported Shields in her MMA endeavor.

The time Conor McGregor slid into Claressa Shields’ DMs

In August 2023, Claressa Shields was gearing up for her MMA return under a new PFL deal, and she got tips from one of the best to ever do it—Conor McGregor. “Conor McGregor inboxed me,” Shields told TMZ Sports: “Conor actually gave me some of the best advice today actually. He was just like, ‘Don’t take away from your boxing. You need to get comfortable being on your back and comfortable with your wrestling.’”

Shields, who went 1-1 in her 2021 MMA stint, admits her biggest challenge has been defending takedowns. With McGregor in her corner and a “reconstructed” team, she focused on evolving her ground game. “That’s an honor and that’s a privilege for me, so thank you to Conor McGregor for that, and I look forward to working with him some[time].” Shields would go on to win her third MMA fight against DeSantis in 2024.

That said, Conor McGregor seems to agree with Claressa Shields’ take on fighting in MMA. Unfortunately, fans won’t get to see Shields in the cage again, and by the looks of things, McGregor isn’t coming back to the UFC anytime soon. Do you agree with Shields? Or do you think she gave up too soon?