reckonerBayesian cable curl
A one arm cable curl with your back to the stack and your arm behind you. The cable keeps pulling all the way down, so the biceps work at full stretch. It grew the biceps as well as a preacher curl did in a ten week trial1, so it is a choice to make for comfort and kit, not a secret.
Arm behind you, curl forward.
- Pattern
- Arm isolation
- Trains
- Biceps
- Kit
- Cable
- Loading
- A weight you choose
- Reckoner prescribes
- 3 sets of 10 to 15 reps at RPE 8
- Progression step
- 2.5 kg once the top of the range is clean
- Skill
- Some technique
- Recovery cost
- Very low
- Not prescribed if you have declared
- Elbow
Muscles worked
How to do it
Set the pulley low and face away
Clip a single handle to a low pulley, take it in one hand and step forward until the arm is pulled back behind your body with the weight lifted off the stack. Stepping out far enough is what keeps tension at the bottom, where this curl is different. Stagger your feet for balance.
Let the arm hang behind you
Start with the elbow straight and a little behind your hip. That stretched start is the reason to do this curl at all, so do not shorten it.
Curl without the elbow moving forward
Bend at the elbow and bring the handle toward your shoulder. The upper arm stays where it started, slightly behind you, for the whole rep, because the moment it swings forward the stretch is gone and the shoulder starts to help.
Lower all the way, then switch arms
Take the handle back down under control until the elbow is straight again. Finish every rep on one arm, then do the other with the same count, so both arms get the same set.
What goes wrong
Letting the elbow swing forward
Bringing the elbow forward makes the heavy part of the curl easier, so it creeps in as the set gets hard. Now it is part curl and part front raise. Keep the elbow pinned behind your hip.
Standing too close to the stack
Standing close feels steadier and the first inches are easy. With no tension at the bottom, the stretched start you came for disappears. Step out until the weight is lifted off the stack with the arm fully behind you.
Cutting the bottom of the rep
The hardest part is the first few degrees out of the stretch, so it is the part people skip without noticing. Straighten the elbow fully every rep, or take weight off.
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
Is the Bayesian curl better than a preacher curl?
Not measurably. In a ten week trial where one arm did each, the biceps grew and strength rose about the same on both1. Pick the one your gym and your elbows like, and keep it long enough to progress.
Should I keep changing curls to hit the biceps from new angles?
Not often. A review of the trials found that some planned variation can help, while changing exercises too often may hold back gains2. Run one curl through a block and progress it.
Will Reckoner put this in my plan?
Not by itself. Placed automatically it would be variety for its own sake, so the engine never chooses it for you. Choose it in the lift picker or as a swap for another curl, and it is logged one arm at a time on the cable stack's own steps.
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
- Attarieh and colleagues, European Journal of Sport Science, 2025. Comparison Between Shoulder Flexed and Extended Positions in Elbow Flexion Resistance Training on Regional Hypertrophy and Maximum Strength: Preacher versus Bayesian Cable Curls fifteen young men training one arm with a cable preacher curl and the other with a Bayesian cable curl for ten weeks, with biceps and brachialis thickness and one rep max rising with no significant difference between the arms
- Kassiano and colleagues, Journal of Strength and Conditioning Research, 2022. Does Varying Resistance Exercises Promote Superior Muscle Hypertrophy and Strength Gains? A Systematic Review a systematic review of eight studies in young men concluding that some systematic variation may help regional growth and strength, while excessive or random rotation of exercises may hinder gains