Watching his highlights reminded me of a story I heard about David Tua. His trainer was trying to convince him to start strength training, Tua had never lifted weights and was hesitant. Trainer sets up the squat rack with some ridiculous amount of weight, like 500 or 600 pounds. Tua unracks it and goes down into a full deep knee bend, butt is an inch off the floor, and presses it back up to a standing position seemingly with little effort, not a groan or a grunt, nothing. The trainer was like "well...guess we're going to have to go up in weight."
Kid is built different.