Study Aids that Helped
I am 48 yrs old and just passed the ACE Personal Trainer Certification Exam on the first try. With 800 being the highest grade and 500 being the lowest, I passed with a 606. I am not involved in the fitness world nor do I work in a gym, and I've never shadowed a personal trainer. I used all the information sent to me by ACE - I think it was the deluxe package. Read and studied the ACE Personal Trainer Manual and still felt very under-educated as far as program design and case studies. Took the advice from other people online who said what helped them in those areas was two books: Exercise Prescription, A Case Study Approach to ACSM Guidelines, and Ace's Guide to Exercise Testing and Program Design. I also used the Exam Prep Course to prepare me for the multiple choice exam. To me, the Exam Prep Course was actually harder than the real exam, which is a good thing.
I used and filled out the two study aids from ACE; Master the Manual and ACE Personal Trainer Home Study Course. Once finished answering all the question I then went back and just read the answers, making myself come up with the question - Jeopardy style. That really helped with memory retention. Use the ACE flash cards and make some of your own in areas of the most difficulty.
Taking another online suggestion I emailed ACE and asked them which formulas do I really need to be concentrating on. They not only sent the formulas, they also sent a math tip sheet to help people like me who have forgotten how to do math long hand. Exams surely vary, these were the formulas needed for the one I took: MHR, HRR, BMI, DBW, some food label percentages, and it wouldn't hurt to know RMR.
Do not let your own opinions and ideas take over - answer all questions as you think would be the most appropriate answer for ACE.
A word about the ACE Personal Trainer Manual; it's no doubt complete in all you need to know about becoming a certified personal trainer - providing you are already working in the field and familiar with everything from anatomy to professional liability insurance. Read it first without getting stuck in any one area, highlighting all areas you think are pertinent. Then read it again, maybe making more flash cards, and it should all start to come together.