Stand behind preacher bench. Grasp cable bar with shoulder width underhand grip. Position back of arms on pad.
Raise cable bar toward shoulders. Lower cable bar until arms are fully extended. Repeat.
Feet can be staggered and bent slightly (if needed) to allow arm pit to rest near top of pad. Back of upper arm should remain on pad throughout movement. The long head (lateral head) of biceps brachii is activated significantly more than short head (medial head) of biceps brachii since short head enters into active insufficiency as it continues to contract. At bottom position, weight stack in use should not make contact with remaining weight stack. Also see movement on horizontal pad.