@ttristbarnes: Do you have to add weight every week to build muscle? No. Overload is one form of stimulus. Stimulus is what grows the muscle. Hammer curl, cable curl, barbell curl. Go properly hard, take it to failure, that's stimulus. The number on the bar didn't do it. More reps at the same load. Better execution. Closer to failure. All of it counts. Do that and the weight goes up on its own. Just don't change the exercise every week or you've got nothing to measure against. Which lift are you stuck on?