I am having a problem finishing a full set with my left arm when doing exercises like alternating hammer curls, but no problem finishing with my right arm. I understand that your dominate side is usually a little stronger, but I am only finishing like 8 of 12 reps by the secon and third sets. How should I handle catching my left side up. (Problem shows up when using barbell as well but not as badly.) Thanks for any help you can provide.