Joshua appears in a new advert for one of his main sponsors Under Armour where he gives an insight into the mental preparation and conditioning ahead of the big fight at the Principality Stadium in Cardiff.

In the latest Under Armour campaign titled 'Your Greatest Opponent is You', there is a focus on the fight against an inner force that athletes must overcome to become great.

The clip directed by directed by award-winning Walter Campbell uses the metaphor of shadows, blended with the training method of shadow boxing, to show the way Joshua aggressively fights negative internal voices as part of his training.

Fight against self

“I've earned this heavyweight, this leather belt and gold plate, and will use the weight of expectation to silence the voices of consternation,” the 28-year-old says in the film as he fights his own shadow in a dark room.

“Inside your head is the great fight because there is always shadow where there was light,' Joshua continues as he pulls on his boxing gloves and punches his way through the wall to reveal the light.”

Reiterating the message of the campaign, Joshua believes that in boxing, the mental is as important as the physical.

“That voice in your head telling you to keep going, to delve deep into your character. You have to make sure that if your body wants to stop, your mind won't let you,” the Nigerian born English boxer said.

“I put the hours in, work harder and smarter than my opponents, but that counts for nothing if my head is not in peak condition. Your body can be hurt and tested, but your will must be invincible.”

Joshua will be looking to continue his perfect professional record when he faces Parker later in March,.

Show he win the fight, the much-anticipated clash against American is expected to follow.