How much time should you really study in college and do good? I know that they say something like 2 hours for every credit but what is more reasonable ?
Honestly, just study as needed. I personally found it amusing that the per-credit rules were recommended. Some classes will be easy and you may not study except right before exams. Others are harder and require better study habits, but it depends on the class and you. Personally I haven’t studied that much in college. If anything, I study less than I did in high school, although I haven’t taken any particularly challenging courses thus far.
Personally, I usually review anything I wasn’t entirely clear on on the day of the class on which it was taught, do all my homework, and review for an hour or two or more before tests. Depends on the class, professor, subject, etc. though. That is sufficient for me to get good grades. For other people, intense review and going through all available practice problems isn’t enough.
I think it depends on you as a person, as well as the subject, class, professor, etc. I usually start each academic term studying very diligently and ease back until I find the appropriate amount of studying for each course. You could try doing the same. Or find another approach. Whatever suits you best.
Also, @runner019 , glad to see another runner here 
My son’s tech school recommends 5-6 hours per day. YMMV.
Criminology: an hour or two right before the exam.
Orgo: as many as ten to fifteen hours, starting days beforehand.
There really aren’t any set rules that apply to every class. Just come in prepared to work, and scale back as necessary.
It also depends on how intelligent you are and how demanding the college is.
Depends. For some of my classes I spent about 1-2 hours max per week, while for others I spent 2 hours every night.
I have really bad study habits so I really couldn’t say. But if I am being productive, what I’ll do is make an outline and then take stuff out of the outline, so that I have a fill-in-the-blanks practice quiz to take.
It’s not about the amount of time you spend studying, but HOW you study. Make sure you are using effective study strategies like quizzing yourself ( like @philpsych describes above or other methods like using Quizlet.com or covering your notes and trying to write down or say the material). People who reread the book, spend time highlighting, or “look over their notes” to prepare for an exam are using ineffective methods no matter how many hours they spend doing it. Self-testing can take time, but it’s worth it because you will actually learn the material!
^^I would agree that methods are very important. If I have a lot of information to memorize, such as in a biology course, I would just take pieces of paper and write down all of the concepts I can remember, or illustrate various processes. (For increased retention I often drew arrows or organized the topics to show how they were connected.) Then I would compare what I had written to my notes from lectures/readings to see what I missed. That always seemed to work well because I was able to identify what I already remembered without prompting and then focus on what I hadn’t recalled.
@thatrunnerkid I actually don’t run that much anymore, lol. When I made my account here I was running about every day. Now it’s not even close, haha!