Cruz has also suffered a lot of lower body injuries in his career, that training and movement has kept him in the upper echelon, but it's also extracted a price, without a doubt.
Fighters put on weight later on which makes it harder to shift your legs and your legs have to carry the rest of your body and, on top of that, keep moving, but your arms don’t
That guy has also had 4 ACLs and spent a huge amount of his career on the shelf. I been a Cruz fan since the WEC. Cruz is an amazing fighter with some of the best footwork MMA has ever seen but lets not pretend that his hyperactive feet aren't partly responsible for some of those injuries.
Legs deteriorate faster than are in real life not just boxing because of the weight above them which they are supporting wears the knees and tendons and cartilage out quicker
I think anything used a lot is going to wear out more, and the legs and feet have all of our body weight. So they will wear out before the arms and hand.. Just my feeling. I am older now. and my legs don't move as well at all, but my hands still seem fast. I can still move my hands and arms I feel similarly than I did 30 years ago yet they get more tired earlier. but I don't think I can run down the street anymore. I could then.