Another thing to note is you will “notice” more muscle definition the less overlaying tissue you have covering it (i.e., fat and skin).
Prior to my arm lift, I needed to flex to see see any muscles. After the arm lift, they could be clearly “noticed” with my arm just hanging by my side (full disclosure: my muscles are in hiding again these days due to pandemic laziness, lol)
But of course, just because you can’t see or notice them, doesn’t mean they aren’t there! Best way to determine lean muscle mass gain is to get scanned.
Good Luck! ❤️