Hold a single-arm handle attached to a low cable with the palm up. Curl the arm as far as possible, then lower under control.
 
Purpose
The single-arm cable curl generally keeps a more continuous level of tension on the biceps than a dumbbell or barbell curl and is a good general bicep strength or hypertrophy choice. The single arm variation is a good choice to establish or maintain symmetry from side to side.
 
Programming
Generally 6-15 reps are appropriate.