Nathan Cleverly insists testing sparring sessions with heavyweights Dereck Chisora and Tyson Fury have strengthened his belief in his "granite chin".
Cleverly will make the fourth defence of his WBO light-heavyweight title against Robin Krasniqi when he headlines Frank Warren's 'Rule Britannia' bill at Wembley Arena on Saturday night.
In an effort to add variety to his training, the 26-year-old Welshman has sparred with Chisora and Fury - and often found himself unloading in ferocious toe-to-toe exchanges.
"It's nice to be taken out of your comfort zone and face guys who are heavier than you and who can push you around," Cleverly said.
"It's good to not have things your own way and these guys test your chin and how you respond.
"Sometimes I stand and trade with the heavyweights. It's macho, you could say it's a bit silly, but that's my mentality. I love to go to war sometimes.
"I have a granite chin and have never been put down, but the heavyweights really test my chin. It's a challenge but it gives me confidence when I take their shots.
"My chin is one of my greatest strengths, which is good because if you're going to get punched for a living you need that.
"In an ideal world you learn how to avoid punches, so I've got to learn how not to be so reckless and make it easier for myself."
Unbeaten in 25 fights, Cleverly's greatest enemy has been the inactivity that restricted him to just two appearances since outpointing domestic rival Tony Bellew in October 2011. In contrast Bellew has fought four times.
Boxing politics and cancelled fights - he was originally scheduled to meet Germany-based Kosovan Krasniqi last year - have proved frustrating and forced him to re-evaluate his relationship with Warren.
But at a time when the likes of Ricky Burns and George Groves have left Warren for Eddie Hearn's Matchroom stable, Cleverly remains aligned with the promoter who steered him to a world title.
"You could say this period of inactivity has tested my loyalty to Frank. It's been a testing period for everyone," he said.
"I've showed loyalty and he respects that. He has respect for me as a fighter and as a person.
"And I respect him as a great promoter and someone who has spoken openly to me.
"It's been an inactive period for me, but sometimes boxing politics gets involved.
"Some fighters don't want to know me because I'm a dangerous opponent. They're staying clear of me.
"It can be hard to track down those guys and nail those big fights. We've had to keep active and take what's available.
"The opposition hasn't been of the highest standard, but they've been game and have had nothing to lose."
Cleverly is seeking a showdown with veteran Bernard Hopkins, the age-defying 48-year-old IBF champion, who will meet former Cleverly victim Karo Murat on July 27.
But before that contest can happen, Cleverly must dispatch another game fighter with nothing to lose in Krasniqi, who has won all but two of his 41 fights.
"It's a huge dream for me to win the world title. This is all I'm focused on because it will change my life," Krasniqi said.
"Every minute of training, every drop of sweat and every round of sparring has been for this moment and this dream.
"I want to make London part of my history - as the place where I won the world title."Tags: Nathan Cleverly