But when you're one win away from a spot in the finals of Bellator's Heavyweight Grand Prix tournament, you have to be willing to do whatever it takes.
"It was so much wrestling. Way beyond what my normal life is," Mitrione said on Ariel Helwani's MMA Show this week. "Out of 10 practices in a week, seven were wrestling practices. Out of the three that were not wrestling practices, two of the three involved wrestling warms, wrestling after I was done, wrestling drills. It sucked. It was my least enjoyable camp ever."
Of course, there's a major reason why Mitrione's regiment is different than it was before. He's facing a fighter in Bader who was a two-time All-American wrestler at Arizona State who won three Pac-10 titles in his weight class.
He used those skills to earn wins in the UFC against fighters such as Quinton "Rampage" Jackson, Ovince Saint Preux, Rashad Evans and Ilir Latifi. Bader joined Bellator last year and has won both of his fights to this point.
Mitrione, in contrast, doesn't have the same pedigree. He played football at Purdue University, starting 35 consecutive games at defensive tackle, but broke his foot his senior year and went undrafted in the NFL. He eventually made a few teams, but after being released by the Vikings in 2005 he left the sport and turned to mixed martial arts.
Fast-forward 15 years later and he's one of the best heavyweight fighters in the world. After a long career with the UFC, he joined Bellator in 2016 and won his first four bouts. This includes a first-round knockout win last year against a fighter some consider the best ever: Fedor Emelianenko. He followed that up with a majority decision win against Roy Nelson in February.
Mitrione says the extra wrestling training has him feeling more confident than at any time in his career.
"I don't care how (Bader) thinks he prepared for it. I'm the anomaly. I'm the different one," Mitrione says. "What Bader does isn't really different from what a lot of people with a wrestling background do. What light heavyweight moves like I do? There's not."
The winner of Friday's fight at Mohegan Sun Casino in Connecticut will move on for a chance to become Bellator's heavyweight champion against either Emelianenko or Chael Sonnen. That matchup takes place at Nassau Coliseum on Long Island on Saturday night.
Sonnen was asked by Helwani who he would prefer to fight for the belt.
"I would like to see Mitrione win, but I think Bader wins," Sonnen said. "Mitrione is an easier match. When you're thinking about your style versus some other guy's style, I do like the size of these heavyweights. I like being the faster guy. I would be faster than Bader too, but it would be closer. I like speed. I would prefer to fight with Mitrione."
Mitrione, appearing later in the studio that afternoon, responded.
"He'll have a really hard time getting that out of his mouth if we ever fight each other because my fist will be straight down his throat. He assumes I'm less of a wrestler. But it's the same as Bader, right?
"For you to get me to the ground, you have to get a hold of my body, and not many people do that very well. If I get taken down, I get taken down to the wall. I'm not getting taken down by Bader or Chael. That's just the way it's going to be."