Gym cat
A chick who goes to the gym on the regular, but not to flirt, or get attention; she's there to lift heavy and grow muscles; not necessarily a young girl but more likely a legit milf; one you'd love to get to know but are more than a little intimidated by; bodybuilder; knows her shit; a twist on the gym rat; the total package.
That Lady is a real gym cat; she can lift heavier than my bro Joe.