For me, it really depends on what kind of studying and how focused it is. If it's solo studying in the quiet area of the library with no distractions for someone who has a good science background and the ability to assimilate knowledge quickly, you can probably do fine with a 1:1 or 2:1 ratio of credit hours to weekly study hours (but you maybe 3:1 or 4:1 during exam weeks). If "studying" is meeting with a chatty group and frequently taking breaks to talk on the phone or play on your laptop, then maybe you do need the 4:1 ratio every week just to pass.
Eventually, after you have LEA and have been performing well for a couple semesters, you also want to put in some hours that aren't necessarily studying for classes and exams but just for personal enrichment and to stay ahead of the curve. That means clinical books and presentations, podiatry magazines, journals, research, etc. Grades are certainly very important, but they're not the come all and be all of learning. A lot of your classes, especially those with a non-cummulative final exam, just test your short term memory and ability to spit out word associations. It's hard to gauge how much you are really grasping until you start to apply your knowledge to patient cases.