Fighting for a living is a tough business. No one knows that better than Sean Sherk, who appears on the cover of the April 2007 issue of FLEX. Less than six months ago, Sherk found himself fighting for a UFC title for the second time in his eight-year mixed martial arts career. Bloodied, from an elbow to the right eye that opened up a gash that would later require stitches, and bruised — from a torn rotator cuff and a torn biceps — Sherk managed to find it in himself to gut out a unanimous decision over Kenny Florian at UFC 64 and win the lightweight title.

Sherk, nicknamed “The Muscle Shark” because of the 180 pounds of muscle he packs on his 5-foot-6 frame, attacks the weights religiously. In addition to his martial arts training and his cardiovascular work, he’s in the gym six days a week, hitting each bodypart once each week. He credits that dedication to making a difference in the octagon.

“The work ethic is a big, big attribute,” Sherk says. “A lot of people don’t have the willpower to train six days a week, three times a day. That for me is my biggest attribute. That’s what actually shows when you’re in the cage fighting. I’m able to fight a lot harder because I train a lot harder. I’m banking on the fact that my opponents at some point in time are going to get tired. And I’m not.”

For more with Sean Sherk, pick up the April issue of FLEX, on newsstands now.