caveat: note the "pre-medical" under my avatar....
In my post-bacc world, I'm not studying much....there were some exams in bio for which my total study time was 5 hours (that was abnormal, but whatever). In UG, I worked, studied, etc, but I never counted hours, I just did it till I was done, or till I was just no longer accomplishing anything.
I'm a little terrified of this 9-5 learning gig b/c I'm not sure I'll be able to sit down for that long -I might have to go for a walk with flashcards or something...
That aside, no one should study for 14 hours straight -"cramming" is totally inefficient. Now, if you're planning a 14 hour day so that you can take many breaks to eat, move, take a nap, etc, then that's different.
I've found, in UG classes, there's a point at which you reach "B" (80-90%) range, and getting there, for me, took about as much time as it took me to get from "B" to "A" (eg 90-100%), for any given course. So if I studied 5 hours to get to 80%, I studied another 5 hours to get to 90%, and another 5 to get to near-perfect.
Do you have practice questions from your instructors? How are you doing on those?
Another way to look at it (from the schoolteacher I am...)
1st = 100% input (lecture/reading book/lab)
2nd = assisted output (multiple choice questions)
3rd = unassisted output (short answer/teaching someone else)
You have to do these in sequence, but within one topic (say, the Krebs cycle) you do all 3 at the same time -you may be able to go straight to #3 with the easy concepts/terms you've seen before, but may be stuck at #1 for a month with the concepts which are just unnatural to you, or the wierd crap you just can't seem to remember. But don't waste too much time on input, without moving to problem sets, because you need to do problem sets to retain the information (use it or lose it).
Also, repeating input (reading the same chapter 3 times) can help comprehension, but may not help memory, because your brain will get bored and stop filing the information. You need to change up your "input" in order to make yourself pay attention -unless you just didn't understand it the first time you read it, or you have completely forgotten something. This is why highlighting text/ taking notes works for some people -that small change makes your brain less bored. Rewriting notes is a form of that. Personally, I hate rewriting notes, but whatever works for you...