Pros are pros, but you are not one (are you?), you don't have the experience, the time, the regeneration, the genes, the attitude, the money. So you might as well ignore most of what they do, because you are not one of them.

> Sure you won't feel a loss of energy, because you've never had that energy in the first place. I don't understand why you would remove a major fuel source entirely.

That's a bold statement. Have you ever tried it? Did you have energy?

Imagine that you don't bonk, no matter if you eat or not, and you can still keep roughly the same level of intensity for the entirety of your session, however long it might be. As a matter of fact, you feel just as fresh mentally at the end as at the start. That's why.