He started MMA late in life, neck aside has an unremarkable injury history, stays in good shape but moves like he's in his 60s, still punches hard and can manage kicks below the waist but can't wrestle anymore, and the best that can be said about the past seven years of his career is that he beat Alex Polizzi. He's still a huge outlier in terms of being able to fight at all at his age, but he's a pretty ordinary outlier. Mostly, he's wanted to keep fighting so he's 1) stayed in fighting shape despite how much work that takes as you get older and 2) been a bit lucky with injuries. Some people just don't get tired of the grind.