Within the space of five years, Anthony Joshua has progressed from being an amateur Olympic hopeful to one of the most feared men on the planet.
There's no doubt Joshua will receive the sternest test of his professional career to date on Saturday when he takes on former heavyweight world champion Wladimir Klitschko at Wembley.
His Ukranian opponent may be 40-years-old now and hasn't been in the ring for nearly 18 months, but underestimating someone who has previously dominated the heavyweight division is an amateur error.
So far during Joshua's relatively short career as a professional, the 27-year-old has fought 18 times, picked up 18 knockouts and in truth has rarely looked in danger of losing.
As well as his natural ability, Joshua's impressive record is also partly down to his extremely powerful physique.
The man who can take some credit for that is his physiotherapist Rob Madden.
Madden has been part of Joshua's team since 2013 and has opened up on how his client likes to prepare for a fight.
He insisted that very little has changed in their training since the IBF champion burst onto the professional scene, despite the standard of opponents gradually increasing.
In fact, Madden revealed that in the immediate aftermath of Joshua's first few pro fights - which he won within the opening two or three rounds - he would go out and train just hours after making his ring walk.
"In the early fights, he would go backstage afterwards and hit the bag," Madden told the Daily Express.
"The training has evolved as his career has gone on - it would be crazy if they hadn't - but really the pillars of what he does are the same."
"He's got the same coach he's always had and he has a phenomenal amount of trust and faith in that relationship.
"Rob [McCracken] does the same stuff with him each camp. Obviously, they work on weaknesses and build on strengths and as support staff we have a routine that we try to get better and better as we go but we don't change anything."
That's surely the sign of a true champ! Joshua is unlikely to have it so easy on Saturday, however.
Klitschko will make his way to the ring at Wembley as the underdog but the Ukranian's unorthodox style has the potential to cause his British rival problems.
And Madden is excited to see how Klitschko handles Joshua's power as the fight progresses.
He added: "AJ's power expenditure is phenomenal.
"We've got the data on that and if you look at the kind of force he can generate through his lower body and out to his arms is amazing.
"His ability to generate force with speed repetitively is one in an million or even more. Probably the best fight to demonstrate that was against [Dominic] Breazeale.
"He took so many hits but AJ was able to go for six or seven rounds at an incredibly hard work rate.
"He's never gone longer than that so it will be interesting to see what happens on Saturday."News Now - Sport News