
Icl stairmaster could be replaced with anything else such as incline treadmill or eliptical as those will be less fatiguing allowing you to allocate more of your energy to training harder while also improving recovery, thus growing bigger glutes. I mean maybe if you’re a complete beginner you’ll see some growth but after a certain point the amount of mechanical tension needed to stimulate growth in your glutes would be impossible to achieve on the stairmaster. Really all you need are hip thrusts