It's unlikely anybody envies Wladimir Klitschko right now, especially if Anthony Joshua's latest Instagram photo is anything to go by. 

The undefeated heavyweight, already renowned for his excellent conditioning, appears to be in equally peak shape as his scheduled title defence approaches.

Joshua, who currently holds the IBF heavyweight belt, will also be challenging for the vacant WBA and IBO heavyweight titles when he meets Ukrainian veteran Klitschko on the April 29.

Joshua, currently undefeated, boasts an 18-0 record, with all 18 victories coming by the way of knockouts.

His opponent is no shrinking violet, however.

The 41-year-old Klitschko, the younger of the Klitschko brothers, has previously held all three belts and holds a distinguished 64-4 record (58 of which were KO's).

The fight has broken box office records with over 80,000 tickets sold at Wembley Stadium. Eddie Hearn has reportedly requested 5,000 additional tickets be made available for the fight.

The significant attention surrounding the match-up comes after disappointing cancellation of the Klitschko/Fury rematch last year, as a result of Fury being "medically unfit."

A Telegraph article reported on Joshua's grueling 4,500 daily caloric intake, a diet so extreme that the average male would be required to run "two complete marathons" a day to burn off.   

Judging by Joshua's photo, he hasn't cut any corners in preparation for his biggest fight yet.

With the opportunity to unite the three belts, and the chance to face Klitschko (easily the highest profile fighter Joshua will have ever faced), you'd expect nothing less than 100% from the talented British heavyweight.