Yesterday was suppose to be an off day but found myself home alone and made it an arms day. Started off with preacher curls. I did 1 warmup set, then got after it. In the middle of my 3rd set I just couldn't move the weight. There was no burning, no pain, just nothing at all. I put the bar down, waited 3 minutes and tried again. Same thing happened. I haven't trained biceps in over a week. I can't figure this out because my tricep wo was great. Was able to complete all sets and felt the burning. Any ideas???