Cutting sugar from his diet and spending time in Jeff Horn's orbit has convinced Alex Leapai his best days are still ahead of him.
The former world title contender has locked in the second fight of his boxing comeback, which will take place on the undercard of Horn's maiden WBO championship defence against Gary Corcoran next month in Brisbane.
Leapai, 38, will face Nigerian Roger Izonritei (12-6-0, 11 KOs) as he looks to re-establish himself as a legitimate challenger.
Not bad for a bloke who's just dropped nearly half his body weight.
The man known as Lionheart tips the scales at 109kg these days, having dropped all the excess baggage he put on during his two years out of the sport.
All up, he's lost 44kg since last Christmas, and he's 6kg lighter than when he took on Wladimir Klitschko and became the first Australian to fight for the heavyweight world title in more than a century.
"I didn't lose all those kilos for no reason," Leapai said.
"I'm really focused this time and more determined. And I believe I will bring a world championship back home.
"All the heavyweights out there who are champions - Joseph Parker, Deontay Wilder, Anthony Joshua. I'm coming for all you guys, believe me."
Leapai (31-7-3, 25 KOs) looks fitter than ever and said he could feel it in his fists.
"Four years ago I was pretty big. The punches were hard and solid but too slow," he said.
"Now losing all the weight, I just feel good. Speed kills.
"I'm still going down - I want to keep going down to 105kg."
Training alongside Horn, who beat Manny Pacquiao in July to become an instant Australian sporting icon, hasn't hurt either.
"It's a pleasure to train against not just a world champion... this guy's a legend, an inspiration," Leapai said.
"I can one day say to my kids, 'Hey, I trained against that guy. I've got pictures with that guy.'"
