Physical activity in fasted state: Glucose for brain vs muscles

Question

Let's consider this scenario: You do sports in the morning in a fasted state (i.e. without consuming any calories after waking). Your brain of course needs glucose and your liver probably still has some of it in stock. So it keeps releasing it. Is there a mechanism to prevent the working muscles from consuming the glucose (so that the brain can be supplied longer)? If yes, how does it work?

(Please answer not too technically, so that people outside this area can also understand it.)

Answer 1

In general it is the reciprical action of the hormones of the fed and fasted state — insulin and glucagon — that are responsible for this, together with the differences in hormone-sensitivity of the glucose transporters in muscle and brain. See the accepted answer to this question: During starvation, does the human body do anything to prioritize which organs receive nutrients?.