The lock clam isn't meant to build muscle. It's a warm-up that activates your glutes and primes your nervous system before heavy lifts like squats or bench press, so the right muscles fire and you move better.
The lock clam isn't going to build slabs of muscle on your glutes because you need load. You need load to build muscle. But with that said, what the lock clam is about— activation. It's about getting the nervous system involved, making sure that the right muscles are working and functioning when you go and do the said task. So whether you're squatting, bench pressing, you've got a game on the weekend, activating the muscles before you do that is going to allow the body and the nervous system to use the right muscles and create a level of stability that otherwise you may go back to bad habits.
