My advice about going into a fitness related field is that even if you don't care about the low pay, there is the factor of how you are treated working in that field. Health clubs are not always the most professional environment; I worked in various places for 10 years and it amazed me how it differed from the professional environment. Unless you are going to become a PT or exercise physiologist, I felt I was always seen as "the help."
This is good advice from Crankin, on not just the fitness fields but other fields where the issue of working in sectors/industry areas with formally trained folks, credentialism/having a diploma/degree is useful for the purposes of opportunity mobility and self-development with support by the employer.

GLC, you might want to rethink how to leverage your technical knowledge to another type of role where it's advantageous to at least speak techie lingo/have experience when working as an intermediary between pure techie folks and clients / stakeholders.