How do I keep working fast when my body is wearing out?

You can run a line faster than anyone, and that speed came from years your body absorbed. Now it is sending the bill. That is not you getting weak. It is the honest cost of doing hard physical work at a high level for a long time. The body keeps score. The pride in being the fastest is real, but it can become a trap if it makes you spend a body you cannot replace. Your worth in a kitchen was never only your speed; it is your judgment, your setup, everything you know that the young fast cooks do not yet. That does not wear out. Small step: start protecting the body you have, smarter movements, real rest, help with the heaviest lifts, without shame. Let some of your value shift from your hands to your head. You have proven you are the fastest. Now the wiser move is to last.