Frogman, "professional athletes" practice, every "professional" practices. I made a statement that was taken way out of context, and we're still off to the races about that statement, although it was a very significant statement.
Let me expound on the important elements of that statement. You can not practice "improvisation"; every night that he was on the stage in front of a crowd, he was practicing because every night he was improvising.
I was talking about one uniquely gifted individual who had mastered his very complex instrument some time ago. Since he was performing three nights a week, there was absolutely no need for some kind of ritualistic practicing. Everything he was playing was in his head; this was music he needed to play, and get approval of, not from some teacher at "Julee yard", but from "his public", the people who knew him, and came to see and hear him.
I have never liked what's called "free jazz", it sounds like someone just playing a bunch of notes very fast, but when he played a lot of music fast, it was coherent and I understood it. The only thing I can compare to what he was playing is "Bird's Best Bop"; no matter how fast, and how much music Bird plays, it's coherent. Other musicians can attempt this, but they always fail, he was doing it.
This is as good as I can get in clarifying a unique situation, with a unique individual.
Enjoy the music.