Alternate Incline Dumbbell Curl
Also works: Forearms
Lying back on a bench set to 45-60 degrees, you curl one dumbbell at a time from a fully hanging arm, rotating the palm up as you go. The incline drags your elbows behind your torso, which stretches the biceps long head before the rep even starts — that lengthened start is the whole reason this beats a standing curl.
Own the movement
Set up first, then execute. Every cue below is something you can check on your next set.
Before the first rep
- Set the bench to 45-60 degrees. Flatter is a bigger stretch and a harder exercise; steeper is more forgiving on the shoulder.
- Sit back with your head, upper back and hips on the pad and your feet flat on the floor.
- Let both arms hang straight down, slightly behind your torso, dumbbells in a neutral grip with thumbs forward.
- Pull your shoulder blades back into the pad so the shoulders stay set rather than rolling forward under the hang.
- Expect to need roughly 20-30% less weight than you use standing. Pick accordingly before the first rep, not after it.
Every rep
Breathing & tempo — Exhale through the curl, inhale as you lower. One to two seconds up, a one-second squeeze, three seconds down, with a brief pause at full stretch before the next rep.
Before you load it
- If you have had a shoulder impingement or a biceps tendon problem, set the bench steeper than 60 degrees and build tolerance gradually. The hanging start puts the long-head tendon under load in a position it usually avoids.
Sets, reps & load
Where to start, and what to change when it stops being hard.
Start with 6-10 kg even if you curl considerably more standing — the stretched bottom position is unfamiliar and the first session should be about tolerating it. Add 2 kg only when every rep reaches a fully straight arm with a controlled 3-second negative and the shoulder stays pinned to the pad. If the bottom feels sharp in the front of the shoulder rather than stretched in the biceps, steepen the bench before you add anything.
What goes wrong
The errors that show up most often, and the cue that fixes each one.
Lower until the elbow is fully open and the dumbbell hangs behind your hip line. If that feels like too much stretch, raise the bench to 60 degrees rather than shortening the rep.
Keep the upper arm pointing at the floor for the whole rep and stop the curl when the forearm is vertical. Anything beyond that is the front delt working, not the biceps.
Drop to a dumbbell you can control for a 3-second negative with your upper back pinned to the bench. This variation is about position, not load — the number on the dumbbell is not the point.
Begin neutral and finish supinated, turning progressively through the rep. Supinating early removes the rotation work and leaves you doing a heavier hammer curl.
Why bother
The biceps long head crosses the shoulder as well as the elbow, so it is only fully stretched when the upper arm is behind the body. On an incline bench, gravity puts it there for you: the arm hangs back past your ribcage at the bottom of every rep. Loading a muscle at long lengths is one of the more reliably useful things you can do for growth, and no standing curl variation reproduces this position.
Lying back also makes cheating physically impossible. Your back is on the pad, so there is no hip swing, no lean, no leg drive. That is why the weight you use here will be noticeably lighter than your standing curl — usually 20-30% less — and why the reps you do get are honest ones. The supination as you rise adds the biceps' second job back in, so the muscle is doing both of its functions in the same rep.
Where it fits
First in your arm work, while you are fresh enough to control the stretched bottom position, at 3-4 sets of 8-12 per arm. It pairs well with a shortened-position curl like a preacher or spider curl later in the session — one loads the stretch, the other loads the squeeze. Do not put it after heavy rows if you want to feel anything; the biceps arrive at it already fried.
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
Asked and answered
What bench angle should I use?
45 degrees is the standard and gives a strong stretch. Go to 60 degrees if your shoulders complain at the bottom, and only try 30 degrees if you are comfortable at 45 and want more stretch — the shallower you go, the further behind you the arm hangs and the harder the bottom of every rep becomes.
Why is my incline curl so much weaker than my standing curl?
Because you cannot cheat. Standing, your hips and torso contribute more than most people realise. Lying back removes them, and the biceps starts each rep from its weakest, longest position. A 20-30% drop is normal and is not a sign you have got weaker.
Should I alternate or curl both dumbbells together?
Alternate. Both arms at once on an incline makes it awkward to keep your shoulders back and encourages you to rock your upper body between them. One at a time lets you keep the non-working arm hanging as a counterweight and gives the working arm real rest.
Does the incline curl build the biceps peak?
It biases the long head, which sits on the outside of the arm and is what most people mean by peak. But peak shape is mostly the length of your muscle bellies, which is genetic. Train the long head properly and you will get as much peak as you were ever going to have — no more.