Conor McGregor has admitted he was downing shots of whisky days before he lost to Khabib Nurmagomedov.
The Irishman was choked out by the UFC lightweight champion in the fourth round of their clash in October 2018.
He has since claimed his preparation for the title fight was 'a disaster' - and has now revealed the true extent of the problems.
And as well as boozing in fight week, McGregor claimed he would go on three-day celebrations after replicating fights in his gym.
"I was drinking all bleeding fight week," he told ESPN. "I had venom in me or something.
"I had people holed up in a hotel and I would ring and arrange a fight, they would come to the gym and have a full-blown fight with no headguards.
"I'd have a war, win and knock the guy out and go off and celebrate and come back in three days.
"I wasn't doing what I should have been doing; I've made mistakes and I've been man enough to admit them."
McGregor has not fought since his defeat to the Russian but makes his return against Donald Cerrone in Las Vegas on Saturday.
And he insists he is a reformed character following a hiatus which saw him fined for punching a man in a Dublin pub.
"If I'm in the wrong, I'm in the wrong," he added. "I let people down and that's it. I'm in a position where I must take control of things and not shy away.
"I've never done that in my career and I never will; the people who believe in me and support me deserve better.
"I'm putting in the work and the focused work, that's why were in such good spirits."
