That's right, I said BUM...Gluteal muscles...to the professional population.
The problem with your bum is that while it has potential to be a powerhouse muscle, it is lazy. Like, Homer Simpson lazy, NO, like lounging in a beach hammock while sipping a Mai Tai in Mexico, lazy. Anyways, you get the picture.
If you are thrusting, squatting, squeezing, pulsing and pumping (?), and your rear isn't growing more round and more robust, it's probably because you aren't activating it properly. Poor activation, or "muscle recruitment" is usually the result of a combination of 3 things: 1) a tightness 2) a weakness 3) a lack of neuromuscular connectivity.
Completing 10 repetitions of these 3 exercises before your daily workout will guarantee firmer junk in your trunk and more badonk in your dunk: