Caffeine affects your brain in important ways.

In Brain Circuitry, Brain General Structure and Function, Creativity and Innovation, Sleep by Brainy Days Ahead

A shot of caffeine will definitely get you going and keep you that way for at least a couple of hours. Alternating with short naps and getting the right balance may help you keep your energy and creativity going for quite a while. This article gives a good description of the effects and what is happening to your brain.