Don't do anything unusual for you on Test Day. Studies have shown that breaking routine on a test day (from your study habits) has negative effects on performance. I think everyone has heard the example, "if you chew grape bubble gum when you study, chew grape bubble gum during the exam."
I took the Kaplan MCAT prep course, where we had five full-length simulated exams, given under conditions similar to the actual MCAT. I was comfortable after the fourth exam, so I performed a little experiment.
I have difficulty sleeping the night before big events, and got at most 30 minutes of fitful sleep before each practice MCAT. I was so tired at the beginning of the exam, that it usually took me 30 minutes or so to really get going on the exam. I only got through the first two passages on the PS section in those 30 minutes.
I wondered if I drank coffee before the exam, would the caffeine lift the fog, and allow me to perform better? On my 5th practice exam, I did just that. I was surprised in that while I was no longer sleepy, I couldn't focus. I wasn't wired, I just couldn't focus. It was the strangest thing! I only got through 6 out of 9 passages! Boy am I glad that I did that experiment on the practice test, rather than on the actual exam!!! What I wound up doing on the night before the exam was to turn on the air conditioner and make my apartment very cold. That allowed me to bundle up under the blankets and get a good night's sleep. I was thrilled the next morning when I wasn't groggy at the start of the exam!
So, my advice is that if you are accustomed to drinking energy drinks before or during exams, and you know that it doesn't affect you negatively, then don't rock the boat. Keep doing it. Otherwise, either experiment like me, or just don't do it.
Good luck!
