reckonerDumbbell preacher curl
A one arm curl with the back of your upper arm flat on an angled pad. The pad stops the shoulder helping, so the elbow does all the work. It grows the brachialis and the forearm flexor a little more than an incline curl, and the biceps a little less1.
Arm on the pad, curl and lower slow.
- Pattern
- Arm isolation
- Trains
- Biceps
- Kit
- Dumbbell, bench
- Loading
- A weight you choose
- Reckoner prescribes
- 3 sets of 10 to 15 reps at RPE 8
- Progression step
- 1 kg once the top of the range is clean
- Skill
- Simple to learn
- Recovery cost
- Very low
- Not prescribed if you have declared
- Elbow
Muscles worked
How to do it
Set the arm flat on the pad
Stand or kneel behind a preacher pad and lay the back of your upper arm along it, armpit snug to the top edge. Dumbbell in that hand, palm up. The pad holds the upper arm still so the elbow does all the work.
Curl up without lifting the elbow
Bend at the elbow and bring the bell toward your shoulder. The back of your arm stays in contact with the pad all the way, because the moment it lifts, the shoulder starts to help.
Lower until the arm is nearly straight
Take the bell down slowly until your elbow is almost straight. Control matters most here, where the bell is pulling hardest.
Finish one arm, then switch
Do every rep on one arm, then the other, and keep the same number of reps on both, so the weaker arm is not let off.
What goes wrong
Stopping halfway down
The bottom of the rep is the hard part, so stopping short feels like the set is going well. Lower until the arm is nearly straight every rep.
Dropping into the bottom
Letting the bell fall the last few inches feels like rest before the next curl. It skips the slow lowering that makes the bottom of the rep count. Lower it under control all the way.
Lifting the elbow off the pad
Raising the elbow makes the top of the curl easier, so it creeps in late in a set. The shoulder starts to help. Keep the arm flat; if you cannot, the bell is too heavy.
How Reckoner progresses this lift
Six weeks of this lift, from 10 kg, run through the real engine. Nothing below was typed in: the prescription, the decision and the sentence beside it all come from the same code that writes your week.
| Week | Prescribed | What it did |
|---|---|---|
| 1 | 3 x 10 at 10 kg | More reps 10 → 11 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 2 | 3 x 11 at 10 kg | More reps 11 → 12 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 3 | 3 x 12 at 10 kg | More reps 12 → 13 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 4 | 3 x 13 at 10 kg | More reps 13 → 14 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 5 | 3 x 14 at 10 kg | Deload 40% of sets offFive weeks of building, then one week lighter. About 40% of the sets come off. The load holds and your reps stay where you earned them, so you keep the strength and lose the fatigue. |
| 6 | 2 x 14 at 10 kg | More reps 14 → 15 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. The lighter week is over, so this is back to three sets. |
Real engine output, not an illustration. Every row was produced by running the engine itself when this page was generated.
The full rule, and why the reps move before the load does, is in how Reckoner decides to add weight.
Questions people ask
Preacher curl or incline curl?
Both grow the arms about the same overall. In a twelve week trial the preacher curl grew the brachialis and brachioradialis more and the incline curl grew the biceps more1. In another, the preacher curl grew more near the elbow2. Pick one per block.
Dumbbell or EZ bar preacher curl?
The dumbbell lets each arm work on its own, so a stronger side cannot cover for the weaker one. The EZ bar lets you move more total weight. Reckoner keeps both in the curl group.
Will Reckoner put this in my plan?
Not by itself. Reckoner already places the EZ bar preacher curl, so the engine never chooses this version for you. Choose it in the lift picker or as a swap, and it is logged one arm at a time on the dumbbell rack's steps. Elbow is recorded against it.
Similar movements
Reckoner eases the load first when this lift stalls, and offers one of these only if it stalls again after that. A lift already as light as your kit goes has no load left to ease, so the offer comes straight away. Each of them has a page.
Sources
- Kobayashi, Maeo and colleagues, Journal of Sports Sciences, 2026. Exercise-specific preferential hypertrophy of individual elbow flexor muscles after incline versus preacher dumbbell curl training twenty-one untrained adults training one arm with incline and one with preacher dumbbell curls for twelve weeks, the brachialis and brachioradialis growing more after preacher, the biceps more after incline, and total elbow flexor growth not different
- Kassiano and colleagues, International Journal of Sports Medicine, 2025. Distinct muscle growth and strength adaptations after preacher and incline biceps curls sixty-three young women over eight weeks, with greater growth at the distal elbow flexor site after preacher curls and at the proximal site after incline curls