Lying Supine Dumbbell Curl
Face-up on a flat bench with the dumbbells hanging beside it, so the shoulders sit behind the torso and the long head of the biceps starts under stretch. You supinate as you curl, which loads the biceps in both of its jobs at once: bending the elbow and turning the palm up.
Own the movement
Set up first, then execute. Every cue below is something you can check on your next set.
Before the first rep
- Sit on the end of a flat bench with a dumbbell on each thigh, then lie back and let the arms settle at your sides.
- Start conservatively — 6-8 kg is plenty. The stretched position roughly halves what you can handle.
- Let the arms hang beside the bench until you feel a firm stretch across the biceps, then stop lowering there.
- Turn the palms in to face the bench — a neutral grip — before the first rep.
- Press your lower back and both shoulder blades into the bench so the upper arms stay behind you.
Every rep
Breathing & tempo — Exhale as you curl and supinate, inhale as you lower. Two seconds up, three seconds down, and a deliberate pause at the bottom instead of a bounce.
Before you load it
- The stretched bottom position is where biceps tears happen. Do two light warm-up sets and never bounce out of the hang, however light the dumbbells feel.
- If you have had front-of-shoulder pain or impingement, use an incline bench at 45-60 degrees instead. The flat-bench hang pushes the shoulder further into extension than some shoulders tolerate.
Sets, reps & load
Where to start, and what to change when it stops being hard.
Start with 6-8 kg dumbbells even if you curl 15 kg standing — expect to use roughly half. Good looks like a controlled three-second lowering into the same depth on every rep, with the elbows never drifting. Add 2 kg per hand only once you can hit 12 clean reps with a deliberate pause at the bottom.
What goes wrong
The errors that show up most often, and the cue that fixes each one.
Control the last third of the lowering deliberately and take a beat at the bottom before curling again. The stretched position under load is where a biceps tendon gives way, and speed is what makes it dangerous.
Keep the upper arms pointing at the floor for every rep. If they creep upward, the shoulder is unloading the stretch — reduce the dumbbells until the arms stay put through the whole set.
Halve your standing curl dumbbell for the first session. The stretched start removes most of your leverage, and misjudging it is the most common way people strain a biceps on this movement.
Start every rep with the palms facing the bench and rotate as you lift. If you cannot complete the rotation under the weight you picked, the weight is the problem, not the cue.
Why bother
The biceps crosses the shoulder as well as the elbow, so its long head is only fully lengthened when the upper arm sits behind the body. Lying flat and letting the dumbbells hang below the bench puts the shoulder further into extension than any incline bench can, and that lengthened position is where the strongest evidence for biceps growth sits.
The rotation is not decoration. Starting with palms facing the bench and finishing palms-up asks the biceps to do the two things it actually does, and it lets the brachialis carry the early part of the rep before the biceps takes over. Drive the little-finger side of the handle up to finish the supination.
Where it fits
First biceps movement of the session, while the elbows are fresh, 8-12 reps. The stretched start makes it the most demanding curl variation on the tissue, so two or three sets is enough, and it does not belong the day before heavy pulling. Do not stack it with another deep-stretch curl in the same session.
If this one isn't it
No kit, too hard, or too easy — here's where to go instead.
Same job, different kit
Start here instead
When this gets easy
Asked and answered
Is this better than an incline dumbbell curl?
It puts the shoulder into more extension, so the long head starts longer. Whether that is better depends on your shoulders — the flat-bench version is the more aggressive stretch and the less forgiving one. If both feel fine, they are close enough that you should choose on comfort and rotate between them across a training block.
Why do I feel this in the front of my shoulder?
Either you have let the arms hang past what the shoulder can hold under load, or the shoulder blades are rolling forward off the bench. Press both shoulder blades down, stop the lowering at the first real stretch in the biceps rather than the deepest hang you can reach, and use lighter dumbbells.
Do I have to rotate the wrist as I curl?
It is the reason to do this with dumbbells rather than a bar. Supinating under load recruits the biceps beyond what elbow flexion alone does, and it costs nothing. If the rotation is uncomfortable right at the bottom, start neutral and rotate a little later in the rep, but do not drop it.
Both arms at once, or alternate?
Both at once. Alternating leaves one arm hanging in the stretched position while the other works, which is a lot of unnecessary time under tension in the most vulnerable part of the range. Curl them together and take your rest between sets, not in the middle of one.