I am female, 145 pounds and 170cm tall. I go to gym 4 times a week and do split training. I have noticed quite some gains on my legs but not really my ass. Here is my workout: (I am not sure of what weight I use, hence if I don't mention it... I don't know- but its heavy to the point where my 9th or 10th rep is basically impossible)
Seated leg press (100kg, 3 sets, 10 reps per set)
Squats (20kg- cant go up as I find it to hard to get the bar over my head, 3 sets, 10 reps per set)
Leg extension (3 sets, 10 reps)
Leg Press (5 sets, begin at 70kg and go up to 100kg and then back down again- is called doing a pyramid)
Then go onto do calves....
Is my butt just taking its time to grow? or are these exercises not adequately working my butt?
I get enough protein, sleep and nutrition :)