Ben Rothwell can breathe easy heading into his return to bareknuckle boxing.

Fighting in Denver may be worrisome to many, given it’s over 5,000 feet above sea level, but not for Rothwell. Ahead of his BKFC 41 bout against Josh Copeland, the former UFC heavyweight contender took his training camp to Team Elevation in Denver to make sure he’s acclimated to the altitude.

This has brought Rothwell a new level of confidence, as he promises cardio won’t be an issue this Saturday.

“The training partners that I had, to my pleasant surprise, were really surprised with how good my cardio was, and I had guys rotating in on me,” Rothwell told MMA Junkie Radio. “I went to a gym, and they put me in the middle and had three guys come in on me, and I handled it very well. They were like, ‘Wow, you did really good.’ I did feel it and I didn’t do as much as I normally did, so I knew that I was like not doing my best. So I was just kind of like, ‘Cool, I’m glad you guys think so,’ but as the weeks went on, that all changed and I really got into my groove.

“I can pretty much go until everyone was done. I’m feeling really good.”

Rothwell was originally scheduled to fight Josh Watson, who came to fame after knocking out ex-NFL star and UFC veteran Greg Hardy earlier this year.

Rothwell doesn’t mind the opponent change and sees Copeland, although a short-notice replacement, as a formidable foe.

“The day before the press conference, he sent a message, ‘I never agreed to fight in Denver,’” Rothwell said regarding the opponent change. “I don’t think he made the promotion very happy. What kind of excuse is that? He kind of blamed the promotion. It’s silly. It kind of leads me to believe that he didn’t really want to take the fight to be honest. I don’t care. He has to live with it. I’m here to fight.”