The cable preacher curl is a single-joint arm exercise that builds strength and size in the biceps using a cable stack and a preacher bench. It is popular in muscle-building arm workouts because the angle of the bench effectively removes the shoulders from the movement, largely isolating the biceps. It is generally performed for higher reps, at least 8-15 per set.
Cable provides constant tension throughout the movement, including at peak contraction
Easy to quickly switch weights for dropsets
More comfortable on the wrists and elbows than a straight bar