Stand with a dumbbell in each hand at arm’s length and the palms facing forward. Curl the weights up in the supinated position, then at the top, rotate the palms to face forward, and lower under control in this pronated position. Supinate the hands at the bottom to start the next rep.
 
Purpose
The Zottman curl is a way to train more aspects of the bicep and forearm in a single exercise. Reverse curls tend to be weaker than supinated, so by lifting supinated and lowering pronated, heavier weights can be used.
 
Programming
Generally sets of 8-15 reps are appropriate.