Should this come before or after heavier curls?

Most lifters place it after heavier two-arm curls such as the Dumbbell Curl or barbell curl, as strict single-arm work once the main sets are done. It can go first on a day when the biceps are the priority.

Can I rotate my wrist during the movement?

Keep the palm facing up for the whole rep and the wrist straight rather than curled toward you. Starting with the palm facing in and turning it up as you curl is a valid variation, since turning the palm up is also a job of the biceps.

Should I fully extend my arm at the bottom?

Lower until the arm is straight or very nearly straight, under control, so the biceps works through the stretched range where the preacher curl loads it hardest. What to avoid is letting the dumbbell drop into lockout or forcing the elbow past straight.

Does the preacher curl build the biceps peak or the short head?

Not specifically. Both heads of the biceps work together on every curl, and the shape of the peak is largely inherited. What the preacher position does shift is the balance among the elbow flexors: a 12-week study in untrained adults who trained one arm with dumbbell preacher curls and the other with incline dumbbell curls found the preacher arm grew more in the brachialis and brachioradialis, the incline arm grew more in the biceps, and total elbow flexor growth was similar.

Why are my biceps so sore after preacher curls?

Lowering a weight while the muscle is stretched causes more soreness than work at short muscle lengths, and the preacher curl loads the stretched bottom of the range. The soreness eases within a few days and drops sharply once you have done the exercise a few times, so start with a lighter weight and fewer sets.

Can I do it without a preacher bench?

Yes. Draping the arm over the back of an incline bench set fairly upright gives a similar braced position, and the Dumbbell Exercise Ball Preacher Curl uses a ball in place of the pad.

Dumbbell Single-Arm Preacher Curl

What Is the Dumbbell Single-Arm Preacher Curl?

Dumbbell Single-Arm Preacher Curl is an isolation exercise that primarily targets the biceps and also engages the brachialis and brachioradialis. It is a beginner-level movement known for its strict form and focus on muscle control.

By training one arm at a time, this exercise keeps the stronger side from taking over and helps even out imbalances between the arms. The preacher bench supports the upper arm and eliminates momentum, making it easier to concentrate on the biceps contraction throughout the full range of motion.

With the upper arm resting on the angled pad, the dumbbell is hardest to move in the lower half of the curl, where the elbow is fairly straight and the biceps is stretched, and the load fades as the forearm approaches vertical at the top. That lower range is worth using in full: a study in which untrained women trained one arm in only the bottom half of a seated dumbbell preacher curl and the other arm in only the top half found the bottom-half arm gained more strength across the full curl and more size in the lower part of the biceps, with similar growth at mid-arm.

Using a dumbbell allows for a more natural wrist and elbow path, which can be more joint-friendly than barbell variations. It usually sits late in an arm or pull session as strict hypertrophy work, and it suits beginners who struggle to keep their elbows still on standing curls. Without a preacher bench, the Dumbbell Concentration Curl gives a similar braced, one-arm position.

Muscles Worked

MuscleActivation

Biceps Brachii: Primary
Brachialis: High
Brachioradialis: Medium
Flexor Carpi Radialis: Low
Flexor Carpi Ulnaris: Low

Instructions

Set the seat so that, sitting tall with your feet flat on the floor, your armpit rests snugly against the top edge of the angled pad.
Hold a dumbbell in one hand with an underhand (supinated) grip and lay the back of that upper arm flat on the pad.
Rest your free hand on the pad for balance and keep your chest close to it.
Start with the working arm straight or very nearly straight and the wrist in line with the forearm.
Curl the dumbbell up by bending the elbow, keeping the upper arm pressed into the pad.
Stop when your forearm is close to vertical and the dumbbell is near shoulder height, and squeeze the biceps briefly.
Lower the dumbbell slowly until the arm is straight or very nearly straight again, without letting it drop into the bottom.
Complete all reps on one arm, then switch to the other.

Common Mistakes

Rushing the movement
Performing reps too quickly reduces time under tension and increases injury risk.
Lifting the elbow off the pad
Letting the upper arm rise off the pad brings the shoulder into the lift and takes work away from the elbow flexors.
Wrist bending
Allowing the wrist to curl or bend breaks alignment and reduces force transfer.
Using momentum
Swinging the dumbbell takes the focus off the biceps and can lead to poor results.
Skipping the bottom of the rep
Stopping well short of a straight arm cuts out the stretched range where the dumbbell loads the biceps hardest.
Dropping into the bottom
Letting the dumbbell fall the last few inches jolts the elbow while the biceps is stretched and its tendon is under load.

Injuries

Dumbbell Single-Arm Preacher Curl is a low risk exercise when performed with proper technique. The fixed-arm position provided by the preacher bench helps minimize the involvement of the shoulders and back, reducing injury risk.

The main strain point is the front of the elbow at the bottom of the rep, where the biceps tendon is loaded with the palm up and the elbow nearly straight. Letting the dumbbell drop into the bottom, bouncing out of it, or choosing a weight too heavy to control there can strain the tendons around the elbow, and a load that pulls the elbow past straight stresses the joint itself. The wrist can also ache if it bends back under the dumbbell.

To reduce injury risk, lower the dumbbell under control to a straight or nearly straight arm without letting the elbow snap into lockout, and keep the wrist in line with the forearm. Use a moderate weight that allows for a smooth, controlled motion without jerking or swinging the dumbbell. If the bottom position bothers the elbow, use a lighter dumbbell, stop slightly short of straight, or switch to the Dumbbell Curl, which barely loads the arm at the bottom. Progress with more reps or a slower lowering phase before adding weight.

Stop the set if you feel sharp pain at the front of the elbow, a pop, or sudden weakness turning the palm up, and get it checked rather than training through it. Mild biceps soreness a day or two later is normal, especially when preacher curls are new to you.

Overview

Primary Focus: Biceps
Equipment: Dumbbell and bench
Modality: Strength
Difficulty: Beginner

Alternative Exercises

Frequently Asked Questions

Q: Should this come before or after heavier curls?: Most lifters place it after heavier two-arm curls such as the Dumbbell Curl or barbell curl, as strict single-arm work once the main sets are done. It can go first on a day when the biceps are the priority.
Q: Can I rotate my wrist during the movement?: Keep the palm facing up for the whole rep and the wrist straight rather than curled toward you. Starting with the palm facing in and turning it up as you curl is a valid variation, since turning the palm up is also a job of the biceps.
Q: Should I fully extend my arm at the bottom?: Lower until the arm is straight or very nearly straight, under control, so the biceps works through the stretched range where the preacher curl loads it hardest. What to avoid is letting the dumbbell drop into lockout or forcing the elbow past straight.
Q: Does the preacher curl build the biceps peak or the short head?: Not specifically. Both heads of the biceps work together on every curl, and the shape of the peak is largely inherited. What the preacher position does shift is the balance among the elbow flexors: a 12-week study in untrained adults who trained one arm with dumbbell preacher curls and the other with incline dumbbell curls found the preacher arm grew more in the brachialis and brachioradialis, the incline arm grew more in the biceps, and total elbow flexor growth was similar.
Q: Why are my biceps so sore after preacher curls?: Lowering a weight while the muscle is stretched causes more soreness than work at short muscle lengths, and the preacher curl loads the stretched bottom of the range. The soreness eases within a few days and drops sharply once you have done the exercise a few times, so start with a lighter weight and fewer sets.
Q: Can I do it without a preacher bench?: Yes. Draping the arm over the back of an incline bench set fairly upright gives a similar braced position, and the Dumbbell Exercise Ball Preacher Curl uses a ball in place of the pad.