I've been training with weights for about a year now, and while other muscle groups have responded to the training (increase in weights), the biceps seem to be at a standstill. Do they just take longer than other muscles to develop? When I started I did 1x12 @ 25lbs, but couldn't get past 9 on the second set. This went on for a while, til I talked to the wellness center manager and she suggested dropping the 2nd set to 20lbs, which I did. I was able to get through the two sets, so did that for a few weeks. Then it was suggested to me to add 2.5lbs in platemates to the mix. Did this Friday, and was able to do 1x12 @ 25lbs then 1x7 @ 22.5 lbs on the left arm and 1x9 @ 22.5 lbs on the right. Am I just being impatient, or is there something else I should be doing?