Hi how are you. I am certified as a "personal fitness trainer" myself. before getting into the course, the best way I found to decide what specific subject I should try to master in, was to attend "Seminars". So, I suggest you to contact multiple institutes you think will offer you the courses and ask them dates when "Seminars" are conducted. Now the question you might think is, "how will seminars help me?". Seminars are nothing but a short duration introduction to specifics of the course, which will give you insight on "is this what I want?" or "is this what I an understand?". After attending about 5-10 seminars, you will be in a much more better position to decide which subject is most relevant to your interest and understanding. I strongly encourage you pursue qualification in health industry, it is one of the ways to give back to our society/ world :) All the best. God bless.