Looking for synonyms for fitness enthusiast

In my native language, there’s a term for a person who works out and enjoys it, but does not incline towards extremes. Works out regularly, but in moderation, to stay healthy and also because they enjoy the process. No dictionary can help me with this. Fitness enthusiast is the best fit I could find so far by googling around this term, but doesn’t it carry a slightly negative connotation, like a "fitness freak"? Do you have a positive word for this kind of a person in English?