Does "amymore" mean the same as "lately" or "these days"?
Would this be OK to say "I've been working out anymore."?
That is regional and dialectic in the US. I use it myself in certain situations in speech (Middle Atlantic, USA). It will seem quite outlandishly wrong to anyone who is not already familiar with it, and it should be avoided, especially in formal writing.
I might say, "I've been feeling my age anymore."