Britain’s Anthony Joshua says he has made “drastic” lifestyle changes since his shock defeat by Andy Ruiz in June.
Joshua lost his IBF, WBA and WBO heavyweight titles as he was knocked down four times before a seventh-round stoppage in New York – one of boxing’s biggest upsets.
The pair will fight again in Diriyah, Saudi Arabia on 7 December.
“Boxing was always the easiest part for me. The struggle was always keeping my life in check,” Joshua, 29, told AFP.
“There will be no aftershock after the first fight. I will be smarter. Getting knocked down was good.
“I have made some drastic changes, lifestyle stuff. Family, circles, what is important, priorities. The effort it takes to stay on the straight and narrow is challenging.”
The pair faced off on Thursday during an international media tour for the rematch with Ruiz – who fights under a Mexican flag – wearing a sombrero throughout the news conference.
Joshua vowed to regain his titles and insisted “stopping isn’t in my DNA”.
“As long as I have breath in me I will keep on fighting for the passion of boxing,” said Joshua.
“I faced defeat as an amateur in my third fight. If I had stopped then there would be no now. I lost in the European quarter-finals. If I stopped then, there would be no now.
“Everyone in this room has been through certain things where no-one believed in them.
“I am not gun shy and I am looking forward to getting back in there and regaining my belts.”
The bout has attracted criticism since it was announced it would be in Saudi Arabia.