SEATEDSit tall on a bench or Swiss ball.
The benefit: Better form Performing the exercise while seated may make you less likely to rock your torso back and forth ("cheat") as you curl the weight. (Check out these six tricks to get the most out of your workout.)
DECLINELie chest down on a bench set at 45 degrees.
The benefit: Thicker arms Lying on a decline causes your arms to hang in front of your body, a position that challenges your brachialis more.
INCLINELie on your back on a bench set at 45 degrees.
The benefit: Bigger guns Lying on an incline causes your arms to hang behind your body, which emphasizes the long head of your biceps brachii to a greater degree.