He did an interview recently in which he said the set is structured for him to take breaks by sitting at the piano(s) for stretches of time. He doesn’t run around on stage and he doesn’t drink water until after the show.
He’s an amazing piano player. He can do LOTS more than Hey Jude and Let it be.....
I noticed that on a televised concert recently. He would sing one fast song after another, but didn’t move from the microphone, and never stopped to drink water, which I think is a mistake.