Basically any word or short phrase I can think of to mean “a lot of muscle” also implies skinny or almost no fat. Fit, or lithe bring to mind more a track athlete’s body, and buff, ripped, jacked, muscular, ect. generally are though of more like a body builder. The closest thing I can think of is dad-bod but thats obviously still pretty far off as well as being male-specific. Is there even an English word for this?
I’ve actually seen people use the word “powerlifter” for this purpose. Id est using it to describe someone’s physical build even if they are not a full-on powerlifter.