Can I use a bench with back support for this exercise?

No, use a flat bench or a sturdy box without a backrest so you can lean forward and brace your upper arm against your thigh.

How many sets and reps are ideal for growth?

3 to 4 sets of 10 to 12 reps per arm is a good hypertrophy range for most people.

Is it better to train both arms at once or one at a time?

The braced setup only allows one arm at a time, which takes longer than two-arm curls but stops a stronger arm from covering for a weaker one. Start each set with your weaker arm and match its reps on the other side.

Is the concentration curl the best biceps exercise?

Not clearly. In a 2026 study of 15 adults curling at about one-third of their maximal elbow-flexion force, the concentration curl ranked first of four curls for biceps activation, but it was only clearly higher than the hammer curl, not the standard or incline dumbbell curl.

Will concentration curls give me a bigger biceps peak?

They build the biceps like other curls, but the shape of the peak depends mostly on where the muscle attaches, which training cannot change. A bigger biceps looks more peaked, so total size is what you can improve.

Dumbbell Concentration Curl

What Is the Dumbbell Concentration Curl?

Dumbbell Concentration Curl is an isolation exercise that primarily targets the biceps brachii and also engages the brachialis, brachioradialis and forearm flexors. It is a beginner-level movement that is easy to learn and effective for building biceps size and strength one arm at a time.

This exercise involves sitting on a bench and curling a dumbbell with one arm while bracing the working arm’s elbow against the inner thigh. The fixed position isolates the biceps and minimizes involvement of other muscle groups or momentum, making it an excellent movement for focused hypertrophy.

Because of its simplicity and control, the Dumbbell Concentration Curl is popular among beginners and advanced lifters alike. It also allows you to easily spot and correct imbalances between your left and right arm strength or muscle development.

Most lifters place it late in an arm or pull session, after heavier two-arm curls or rows, where moderate loads and strict reps suit the braced setup. It grows the whole biceps rather than reshaping it: how peaked the muscle looks depends mostly on where it attaches, so more peak comes from more total size. If you cannot keep the upper arm still against the thigh, a lighter dumbbell or the Band Concentration Curl is the place to start.

Muscles Worked

MuscleActivation

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

Instructions

Sit on a bench with your legs spread and a dumbbell in one hand.
Lean your torso forward and press the back of your working arm, just above the elbow, against the inside of the same-side thigh.
Rest your free hand on your other knee to support your upper body.
Let the dumbbell hang with your arm straight toward the floor, palm facing your other leg.
Curl the dumbbell up toward your shoulder by contracting your biceps. Keep your upper arm pressed into your thigh and your shoulder down as the weight rises.
Pause briefly at the top for maximum contraction.
Lower the dumbbell slowly back to the starting position.
Complete all reps on one arm, then switch sides.

Common Mistakes

Using momentum
Swinging the dumbbell or moving your torso reduces isolation and increases injury risk.
Incorrect elbow placement
Letting the elbow slide off the thigh reduces stability and leads to poor form.
Shrugging or leaning away
Lifting the shoulder or leaning the torso away from the weight to finish a rep takes work off the biceps and usually means the dumbbell is too heavy.
Rushing the reps
Quick, uncontrolled reps reduce time under tension and the effectiveness of the exercise.
Twisting the wrist
Rotating or curling the wrist at the top can cause unnecessary strain and reduce focus on the biceps.

Injuries

Dumbbell Concentration Curl is a low risk exercise when performed with proper technique.

Since you’re seated and braced, there’s minimal strain on the lower back or supporting muscles. However, poor wrist alignment or jerky movements may lead to forearm or elbow discomfort.

To prevent issues, avoid using heavy weights that force you to swing or lean. Focus on a slow, controlled motion and keep your wrist neutral throughout the curl. If you feel discomfort in your elbow, check your arm placement and keep the back of your upper arm pressed against your thigh rather than letting the elbow slide.

Lower the dumbbell under control rather than letting it drop, because a sudden, forceful load on a lengthening biceps is the usual way the tendon at the front of the elbow is injured. Stop the set if you feel a pop, sharp pain at the front of the elbow, or pain that lingers after training. A lighter dumbbell or the Band Concentration Curl is the regression, and a slower lowering phase or a pause at the top is the progression before adding weight.

Overview

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

Alternative Exercises

Frequently Asked Questions

Q: Can I use a bench with back support for this exercise?: No, use a flat bench or a sturdy box without a backrest so you can lean forward and brace your upper arm against your thigh.
Q: How many sets and reps are ideal for growth?: 3 to 4 sets of 10 to 12 reps per arm is a good hypertrophy range for most people.
Q: Is it better to train both arms at once or one at a time?: The braced setup only allows one arm at a time, which takes longer than two-arm curls but stops a stronger arm from covering for a weaker one. Start each set with your weaker arm and match its reps on the other side.
Q: Is the concentration curl the best biceps exercise?: Not clearly. In a 2026 study of 15 adults curling at about one-third of their maximal elbow-flexion force, the concentration curl ranked first of four curls for biceps activation, but it was only clearly higher than the hammer curl, not the standard or incline dumbbell curl.
Q: Will concentration curls give me a bigger biceps peak?: They build the biceps like other curls, but the shape of the peak depends mostly on where the muscle attaches, which training cannot change. A bigger biceps looks more peaked, so total size is what you can improve.