Bodybuilding Exercise: Dumbbell Preacher Curl

One-arm dumbbell preacher curl is a good exercise for isolating the biceps and making them work independently. The only difference between the dumbbell preacher curl and the barbell preacher curl is that you will be using one arm and holding a dumbbell. Alternate your two arms. Use your free hand to hold on to the bench and keep your balance, or to help the other hand complete extra repetitions at the end of a set. This exercise is designed to isolate and focus attention on the biceps. Therefore resistance is stronger at the start of each repetition. So when you begin each repetition, don’t “swing” your arm to move the weight.

One-Arm Dumbbell Preacher Curl Exercise Instructions

STARTING POSITION (SETUP): Fix the preacher curl bench at an optimum height, such that you’re neither leaning onto the preacher pad, nor is your shoulder being raised due to the excess height of the pad. Grasp a dumbbell in one hand and place the back of your upper arm flush against the angled side of the preacher-bench pad. Brace yourself with the opposite arm for stability.

EXERCISE EXECUTION (MOVEMENT): Lift the weight toward you, keeping your elbow in contact with the pad the entire way. Don’t go fast; if you don’t feel tension building in your biceps, you’re swinging the weight instead of using the muscle to do the work. Once you reach the top — stop just short of your forearm going perpendicular to the floor to maintain tension — lower the weight until your elbow is just short of full extension. Repeat for the desired number of repetitions then change to your other arm.

One-Arm Dumbbell Preacher Curl Tips & Key Points

• Sit firmly on a bench, with your arm hanging over a platform. Your elbow should be low on the platform, with your armpit touching the pad.
• Use the other hand to hold on to the pad to stabilize yourself.
• Slowly and under control curl the dumbbell up while keeping your upper arm in contact with the pad.
• Curl the dumbbell up until your forearm is at about 90-degree angle.
• Stopping a few degrees short of full elbow extension keeps tension on the biceps as the barbell is lowered.
• For forced reps, use your nonworking hand to assist in lifting the dumbbell up.

Muscles Involved in One-Arm Dumbbell Preacher Curl

• Main muscles: biceps, brachialis, brachioradialis
• Secondary muscles: pronator teres, extensor carpi radialis longus, flexor digitorum superficialis, flexor carpi radialis
• Antagonists: triceps, anconeus

Exercise Variations

Spice up and intensify your routine with these variations. These three variations will help take your biceps workout to the next level.

• One Arm Dumbbell Preacher Curl With Twist. As with the standing exercise, this variant uses the two key functions of the biceps, flexing and supination. Start at the top with your palm facing your shoulder (supination), then lower the weight and at the same time twist your forearm, reaching a neutral position almost at the bottom of the movement. This increases the work performed by the forearm flexors, but it also requires a fair amount of effort from the two heads of the biceps.

• Two-Arm Dumbbell Preacher Curl. You can also use two dumbbells at the same time, in which case the variant is basically the same as the barbell exercise. But those who are new to weight training may recognize a natural strength discrepancy between their right and left arms. To balance arm strength, it’s important to raise and lower both dumbbells at the same speed and in the same range of motion.

• One-Arm Cable Preacher Curl. In this variation of the preacher curls, we use a cable to provide resistance. In this case you will need to position a bench facing the cable station (low pulley).

Replacement Exercises

To add variety to your biceps workout routine, replace the one-arm dumbbell preacher curls with a different exercise from our database that works the same muscles – biceps brachii. Each exercise works the bicep and supporting muscles slightly differently.

• EZ-Bar Preacher Curl
• Straight Bar Standing Bicep Curl
• Machine Biceps Curl
• Standing Hammer Dumbbell Curl
• Dumbbell Concentration Curl
• High-Pulley Curl
• Standing Cable Curls
• Standing EZ-Bar Curl
• Cable Rope Hammer Curls
• Dumbbell Curl Over Incline Bench
• Standing One-Arm Cable Curl

Closing Thoughts

Well defined upper arms are not only impressive, but their strength is called for in many sports. One-arm dumbbell preacher curl totally isolates the showpiece muscles at the front of the upper arms. Because your upper arms rest on the apparatus, shoulder flexion is removed from the lift. That’s why this biceps exercise is a great way to prevent cheating and to provide a perfect biceps contraction by separating the elbow movement from the rest of the body. Furthermore, because this movement is done in a seated position, it is easier on your back than standing curls.