Exercise guide · evidence-graded

Concentration Curl

The concentration curl is a seated, one-arm dumbbell curl in which the back of the working upper arm rests against the inside of your thigh, so the elbow stays fixed and the shoulder cannot swing the weight up. It works the biceps with the brachialis underneath, and it is a strict isolation exercise known for a hard squeeze at the top of each rep.

Also called: DB Concentration Curl, Dumbbell Concentration Curl, Seated Concentration Curl, Braced-Elbow Curl · Equipment: dumbbell · Pattern: pull

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How to do it

Step by step

Sit on the end of a bench with your feet planted wider than your hips and a dumbbell in one hand.
Lean forward from your hips with a long back and rest the back of your working upper arm, just above the elbow, against the inside of the same-side thigh.
Let the arm hang straight down with your palm facing the opposite leg, and rest your free hand on your other knee.
Curl the dumbbell towards your shoulder by bending only at the elbow, turning your palm up as it rises.
Finish with your palm facing your shoulder and squeeze the biceps for a moment, with your upper arm still resting on the thigh.
Bring the dumbbell back down under control, taking about two seconds, until your elbow is fully straight.
Complete all the reps on one arm, then move the dumbbell to the other hand and repeat on that side.

Coaching cues

Upper arm pinned to your thigh
Curl around a fixed elbow
Turn your little finger up at the top
Squeeze the biceps at the top
Straight elbow at the bottom of every rep
Long back over the working leg

In VALDA, these cues are one tap away on the exercise while you train.

Muscles worked

What it trains

Muscle	Role	Evidence
Biceps brachii: short head	Prime mover	A
Biceps brachii: long head	Prime mover	A
Brachialis	Secondary	B
Brachioradialis	Secondary	C
Forearm flexors	Stabiliser	D
Anterior deltoid	Stabiliser	C

Evidence grades: A = strong research base · B = good · C = limited · D = coaching consensus.

Common faults

What goes wrong, and the fix

Pushing off the thigh

Fix: Keep the upper arm resting on the thigh and pick a dumbbell you can curl strictly.

Elbow lifting off the thigh at the top

Fix: Keep the back of your upper arm touching the thigh through the whole rep.

Cutting the bottom short

Fix: Bring the dumbbell down until your elbow is fully straight on every rep.

Resting the bony point of the elbow on the thigh

Fix: Rest the soft back of the upper arm, just above the elbow, against the inner thigh.

Rounding over the working leg

Fix: Lean forward from your hips and keep your back long.

Dropping the dumbbell on the way down

Fix: Take about two seconds to bring the dumbbell back to a straight elbow.

Programming

What the research says

Muscle growth · first choiceRehab & prehabGeneral fitnessEndurance

Muscle activity — In a surface EMG study of eight curl variations, the concentration curl produced the highest biceps muscle activity. Muscle activity shows how hard a muscle is working during the lift, not how much it grows.
Muscle length — Elbow-flexor studies found training with the elbow nearer straight, where the biceps is longer, built more muscle than training near the top of the curl. The concentration curl is hardest near the top, so many lifters pair it with a curl that loads the stretched position.
Load and effort — Research finds muscle growth is similar across a wide range of loads when sets are taken close to failure, and sets that end a few reps short of failure capture most of that benefit.
Volume — Research links more weekly sets for a muscle to more growth, with diminishing returns. There is no research specific to the concentration curl.
Placement — Concentration curls are commonly done for 8–15 reps per arm after heavier pulling or curling work. Each arm is trained in turn, so a set takes about twice as long as a two-arm curl.

Alternatives · VALDA FLEX

Swap it mid-workout

With VALDA Pro, FLEX offers alternatives like these when you swap an exercise mid-workout.

Log the concentration curl in VALDA, with these cues one tap away while you train and your history for it in one place.

General information about exercise technique, not medical advice. If you have an injury or a health condition, your healthcare provider is the right person to ask.