9 Preacher curl
Why it’s on the list: There are many versions of the preacher curl: machine, bar, dumbbell, cable, one arm or two, standing or seated. You can even curl off the straight end of the bench, called a Scott curl after the first Mr. Olympia, Larry Scott. Regardless of which variation you choose, you’ll get a serious biceps pump!
As with other movements that start from a stretched position, you get peak muscle activation and forces during the lower-third of the concentric movement.4 As the wrist moves closer to the elbow joint and eventually past it, it becomes a more advantageous position for the muscle, meaning it doesn’t have to work as hard. This is one reason the cable might be the best implement to use here.
In your workout: Since your arms are against a bench, it’s a very strict movement that doesn’t allow a lot of cheating. Hence, this movement is best done toward the latter half of your workout. You can program it as a long-head movement, since it could theoretically emphasize that head, although no study has verified this.