This is actually one of the most commonly argued "pieces of advice" regarding the MCAT. I used to follow the classic line - don't study the day before, and certainly don't study the morning of your exam. Over time, though, I realized that it's ridiculous to push such an all-or-nothing rule on everyone. The most important thing by far is to know yourself.
If you're the kind of person who can take a break without beating yourself up, don't study. Exercise, eat your favorite foods (though nothing super unhealthy, unusual, or excessive), and just chill. However, most people (and almost everyone on this forum) feel horribly guilty doing this, like they might stumble upon that one question that makes a difference the next day. In that case, do as much non-mentally-taxing work as you can. Look over your notes, review things to memorize (formulas, etc.), and go over old AAMC exams. This last one is a really useful exercise - basically, choose one or two old practice tests and skim through them question-by-question, asking yourself if you would be able to properly approach them now. You can even turn on the solutions while doing this.
However, there are very good reasons behind the common "don't study" approach, and they generally involve these pitfalls. Here are things to avoid doing, no matter what:
1. Obviously, don't take another practice exam. It's generally a bad idea to even take a new section of a practice test. It's exhausting, and more importantly, if you randomly happen to do poorly it can wreck your self-esteem.
2. Don't exhaust yourself. Even if you learn new facts, it'll hurt you much more than it helps, especially with verbal. I've seen students who regularly get 12's on VR get 7's or 8's on practice exams simply because they got 3 hours of sleep the night before.
3. Don't look at new resources! If you've been using Princeton Review Hyperlearning for verbal, don't randomly decide to do a few EK passages for variety. Again, if you accidentally run into that "one crazy hard" passage, you can hurt your confidence for no reason. For verbal, in fact, I actually advise either redoing old passages or completing passages without scoring them (obviously you can look at the answers, but absolutely don't calculate out any kind of numerical score).
4. (this is a big one) DON'T FALL INTO A SPIRAL! For some reason, studying on the last day tends to go like this:
10am: I just want to check and see if diverging lenses produce upright images.
10:15 am: Wait, diverging lenses correct myopia...what is that again?
10:45 am: Hmm, ciliary muscles, they could test those
11:30 am: WAIT do I need to know the cranial nerves
4 pm: Why am I reading about lasers?
In short, you'll end up panicking about random details, which are almost certainly out of the scope of the MCAT. To prevent this, review your notes as much as possible instead of rereading textbooks or resorting to the internet.
In any case, I'm always curious to see what people think about this. I guess my "short" answer would be - you'll hear "don't study" from everyone and they have a valid point, but above all, never do anything that makes you restless or uncomfortable. Good luck!
lol jk...
