Anthony Joshua said he is "still in the battlefield" and quashed any suggestion of nearing the end of his career as the Briton weighed in heaviest for Saturday's world-title challenge against Daniel Dubois.
Two-time unified heavyweight champion Joshua, 34, takes on Dubois, 27, for the IBF belt at Wembley Stadium on Saturday.
Joshua tipped the scales at 18st during an elaborate weigh-in at Trafalgar Square, with Dubois at a career-heavy 17st 10lb.
"I look at myself as a gladiator and I'm going to step into the arena tomorrow to perform for the people," Joshua said.
"I started late in boxing but it shows you can achieve anything. I'm not a warrior in the garden yet, I'm still on the battlefield."
The central London landmark was cordoned off for arguably Britain's most extravagant fight week location ever.
Double decker buses and black cabs provided the backdrop, with Nelson's Column towering behind a stage placed between the two iconic fountains.
Greenwich-born Dubois - just as he was at Thursday's news conference - kept his words to a minimum.
"I'm ready to fight," he repeated three times.
BBC