'I put my head in a bucket of ice, thinking why do I feel so tired?' - Anthony Joshua reveals his struggle before shock defeat to Andy Ruiz Jr

Two-time world heavyweight champion opens up about one of boxing's biggest upsets

Anthony Joshua lands a big right on Andy Ruiz Jr during the British fighter's comprehensive victory in the heavyweight world title rematch in Saudi Arabia in December 2019. Getty

Anthony Joshua celebrates victory over Andy Ruiz Jr. Getty

British boxer Anthony Joshua (white trunks) competes with Mexican-American Andy Ruiz Jr in Diriya. AFP

Joshua lands a right in his fight with Andy Ruiz Jr. AFP

Defending champion Andy Ruiz Jr trades blows with Anthony Joshua. AP

Joshua outclassed Andy Ruiz Jr for a unanimous points victory. AFP

Defending champion Andy Ruiz Jr takes a punch during his fight against Britain's Anthony Joshua. AP

Andy Ruiz Jr after losing on points to Britain's Anthony Joshua. PA

Andy Ruiz Jr trades blows with Anthony Joshua. PA

Andy Ruiz Jr tries to land a left Against Anthony Joshua. PA

Anthony Joshua poses with the IBF, WBA, WBO & IBO world heavyweight title belts. Getty

Anthony Joshua has finally talked about the torment he went through prior to losing his world heavyweight titles in the shock defeat to Andy Ruiz Jr six months ago.

The British boxer defeated Ruiz in their rematch in Saudi Arabia on Saturday to reclaim the WBA, IBF and WBO titles he lost in June and, in doing so, became a two-time world champion.

Conspiracy theories had circulated after his initial defeat in New York, one of the biggest upsets in heavyweight history.

"I had some issue with my health which I was going through for a long time," said Joshua. “I didn't know what was wrong with me. I felt so tired and drained and thought it must be down to training.

"In the changing room before the fight I got a bucket of ice and was putting my head in it thinking 'why do I feel so tired?'

"The responsibilities of being world champion are difficult. All that stuff, feeling so tired, dealing with obligations. Now I have energy, I haven't missed a session."

He added on bbc.co.uk: "After my check-ups it showed what the problem was and this is what you have to get sorted. Even in this camp I had an operation done but as I'd started training in June I had no issues."

Joshua refused to say what the operation was but it is understood the procedure he had was linked to the issue diagnosed after his defeat to Ruiz.

Joshua is targeting a return to the ring in March to defend his belts – although a bout with Deontay Wilder remains some way off.

Fans hoping for that much-anticipated historic unification clash with WBC champion Wilder will have to wait a little longer. The American is slated to take on lineal champion Tyson Fury in February.

Not that the urge to go up against Wilder is not there. Asked about the possibility of meeting the heavy-hitter, Joshua said: "I'm ready. I've got my belts back and I'm ready to fight him. But I'm not looking too far into the future because it takes your eyes off what is front of you.

"I take it step by step and, by the time I get to unification, I will be ready. I'll knock them down one by one and, when the big boys are ready, I'll be ready to become the next undisputed champion of the world. I really want to make that happen."

WBO president Francisco Varcarcel said that Joshua had until June 4 to take on Ukraine's Oleksandr Usyk or he would have to relinquish his belt.

The dangerous former cruiserweight is also represented by promoter Eddie Hearn, which should make a potential clash easier to make happen.

Another potential opponent could be Kubrat Pulev. The Bulgarian defeated Hughie Fury last year to again become the IBF’s No 1 challenger. He was supposed to fight Joshua in Cardiff in 2017, but withdrew because of a shoulder injury.

“The work begins again because around March I'll be defending those titles again,” Joshua said. “I'm already focusing on my next fight.

"Anyone can get it. The resume shows that, but I'll be keen to handle my mandatories because the current WBC champion is fighting with Tyson Fury, so good luck to them both, that's another exciting fight for the division.

"In the meantime, I will handle my mandatories because I don't want to vacate a belt. I've worked hard to get them so I don't want to give them away."

Joshua said to defend his belts "on home soil would be big news" after Hearn revealed he had been in discussions over a fight at Tottenham's new 62,000-capacity stadium, most likely against Pulev.

"It would be mega," Joshua added. "Looking at how many people came out here shows there is still a big interest in the heavyweight division, especially now we are taking the belts back. Sometimes it would be better against a Brit, but if not I follow the mandatories and defend them that way."