Problem:

I've heard that the brain consumes quite a lot of oxygen and energy, compared to the rest of the body.

Question: What I'm interested in is if this is the kind of energy and oxygen that the rest of the body competes for?

Question: Does running divert resources from the brain to the muscles, leading to decreased cognitive performance?

Question: Does digesting food divert resources from the brain to the gut?

Question: Does the heart rate or blood pressure have anything to do with how much resources, like oxygen and energy are available to neurons?

Please explain all the answers(no word limit count).