The concentration curl is the strictest biceps curl there is — one arm at a time, elbow braced, no swinging. Here's how to do it with good form, the muscles it works, the mistakes to avoid, and how to program it.
The concentration curl is an isolation exercise that works the biceps brachii, with help from the brachialis underneath. You sit on a bench, brace the back of your upper arm against your inner thigh, and curl a dumbbell up one arm at a time. Bracing the elbow removes all body English, so the biceps has to do the work through a strict range — which is why it produces such a strong, focused contraction. It's a classic finisher for building the biceps peak and dialing in the mind-muscle connection.
The concentration curl is a biceps isolation move. Bracing the elbow removes the shoulders and momentum, so the biceps does the work almost on its own, with the brachialis assisting underneath.
| Role | Muscles | What they do in the lift |
|---|---|---|
| Primary mover | Biceps brachii | Bends the elbow to curl the weight up |
| Assisting | Brachialis | Helps flex the elbow, sitting beneath the biceps |
| Assisting | Forearm flexors | Grip the dumbbell and help hold the wrist steady |
Step-by-step form for the seated single-arm concentration curl. If you're new, start light — this is a movement you feel, not one you swing.
If you want to train the biceps with a different emphasis or equipment, these are the common swaps:
The concentration curl is an arm accessory or finisher that fits on pull, upper-body or arm days. General starting points:
| Goal | Sets × reps | Notes |
|---|---|---|
| Muscle size | 2–3 × 10–15 | Strict reps per arm, hard squeeze at the top, slow lowering |
| Finisher | 1–2 × 12–20 | Lighter load at the end of arm work to chase a pump |
| Frequency | 1–3× / week | Small muscle that recovers fast; rotate with heavier curls |
The concentration curl pairs well with the dumbbell curl and the preacher curl for complete biceps work. To pick the right rep targets for your goal, read up on rep ranges.
Log every concentration curl set — weight and reps per arm — in LiftHero, and it charts your progressive overload and flags personal records so you can watch your biceps strength climb one arm at a time. You can superset curls with triceps work, add rest-timer holds, and save your arm day as a routine. LiftHero records what you log; it doesn't diagnose your form.
It isolates the biceps brachii, with help from the brachialis underneath. Bracing the elbow against the thigh removes body English so the biceps does the work in a very strict range, which is why it produces such a strong contraction.
Pinning the upper arm against the inner thigh locks the elbow in place so you can't swing or use the shoulders to cheat. That forces the biceps to do the lifting through a strict range and lets you focus on squeezing the muscle.
Not strictly better, just different. Their strength is a very strict, isolated contraction with a strong mind-muscle connection. Standing and preacher curls let you load more weight. Most lifters use concentration curls as a finisher or accessory.
No. Because the position is strict and single-arm, you'll use less weight than on standing curls. Pick a load you can curl without swinging or letting the elbow drift, and focus on control and the squeeze rather than the number.
As an isolation move, moderate to higher reps work well — commonly about 10–15 reps per arm for 2–3 sets. Keep every rep strict and controlled, and train close to failure on the last set for size.
Track your curls, watch your PRs climb, and run a real program — free on iOS.
Download on theApp StoreFree to start · No interruptive ads · 14-day Hero trial
This guide is educational and not medical advice. Consult a qualified coach or medical professional before starting or changing a training program, especially if you're new to lifting or returning from injury.
By Meitar Lazimi, founder of LiftHero · Last updated July 9, 2026.