Nuance between occupation and essential hobby

Question

Hi!

This is a general question I have about words that can both describe a hobby and an occupation. I have been wondering about the example "Soy culturista" (I am a bodybuilder). Would we only say that if we made a living from bodybuilding? Would we say "soy un culturista" instead, if bodybuilding were only a hobby? (I got the variant with un as an alternative suggestion from a translator website.)

Thank you as always!

Accepted Answer

Hola Gabor
I think this question went through the cracks I'm afraid! 
So, to me, saying "Soy un culturista" sounds a bit unnatural, using the article. I'd say that when we refer to an activity that is taken as a "serious hobby", we still drop the article unless you want to be more specific about it and add some extra information, for example:

Soy un culturista extremo que dedica todo su tiempo a levantar pesas.
I am an extreme body builder who dedicates all his time to weightlifting.

Here the article makes more sense. 
Other examples that are not talking about profession but hobbies or ways of living or beliefs (e.g. religion, politics) could be:

Soy vegetariano (not un vegetariano) 
Soy testigo de Jehová (not un testigo de Jehová)
Soy socialista (not un socialista)

I hope this clarified it. 
Sorry about the delay.
Inma