When Im lifting in the gym consistently Im having this issue that I dont see other people having. I will come in and the weight Im at on the first set will be extremely hard to do on my first set. When the secound set comes around I will be able to do it easier but I still have to push. Then when I get to my last set I blow through the weight and it feels light. Wtf am I doing wrong? It mainly happens when I do my shoulder work outs but it has happened to me when I do chest as well.