Single-arm Preacher Curl
The single-arm preacher curl is a dumbbell curl done with your upper arm resting on an angled pad, so the biceps do the work and you can't swing the weight. It suits beginners who want to learn a strict curl, and experienced lifters who want to focus on one arm at a time. Using one arm lets you control the weight and spot any difference between your left and right sides.
Muscles worked
The Single-arm Preacher Curl mainly works your biceps.
Setting up
- Sit at a preacher bench and adjust the seat so your armpit rests snugly against the top of the pad. The back of your upper arm should lie flat along the pad.
- Pick a light dumbbell to start with. This exercise is stricter than a standard curl, so you will usually need less weight than you expect.
- Hold the dumbbell with an underhand grip, palm facing up, and rest your other hand on the bench or your thigh for balance.
- Sit tall with your chest up and feet flat on the floor, then let your working arm hang down over the pad.
How to do the Single-arm Preacher Curl
- Start with your arm extended over the pad and a slight softness in the elbow, so it is not forced fully straight.
- Brace your upper arm firmly into the pad and keep your wrist straight and in line with your forearm.
- Breathe out and bend your elbow to curl the dumbbell up towards your shoulder, with the back of your upper arm staying on the pad the whole way.
- Stop when your biceps feel fully squeezed at the top, before the dumbbell drifts back over your elbow.
- Pause briefly, then lower the dumbbell slowly over about three seconds, breathing in as you go.
- Stop just short of a locked-out elbow at the bottom, then start the next rep. Finish all your reps, then swap arms.
Form tips
- Keep your armpit pressed against the top of the pad so your upper arm doesn't slide or lift off.
- Think about moving only at the elbow. Your upper arm stays still and the dumbbell travels in a smooth arc.
- Take the lowering phase slowly. A controlled three-second descent works the biceps hard without needing a heavy weight.
- Squeeze the biceps at the top for a beat rather than letting the dumbbell just stop.
- Start lighter than you think and add weight only when every rep looks the same as the first.
Common mistakes
Dropping the weight at the bottom
Lower the dumbbell under control and stop just before your elbow locks out. Bouncing out of the bottom takes the work away from the biceps, so slow the last third of the descent.
Lifting the elbow or upper arm off the pad
Keep the back of your upper arm in contact with the pad throughout. If it lifts, the dumbbell is too heavy, so reduce the weight.
Standing up or leaning back to finish reps
Stay seated with your chest up and your armpit against the pad. If you need to move your body to finish a rep, stop the set there.
Bending the wrist
Keep your wrist straight and strong, in line with your forearm, as if you were holding a hammer. Curling the wrist back or forward changes the movement and can feel uncomfortable.
Sets and reps
| Build strength | 3-4 sets of 6-8 reps per arm with a challenging but controlled weight, resting 90-120 seconds between sets. |
|---|---|
| Build muscle | 3 sets of 8-12 reps per arm, lowering slowly, resting 60-90 seconds between sets. |
| Fat loss and general fitness | 2-3 sets of 12-15 reps per arm with a lighter weight, resting 45-60 seconds, as part of a wider full-body programme. |
Pick a weight where the last rep or two of each set is hard but your form stays clean. When every set feels easy, it's time to go up.
Single-arm Preacher Curl alternatives
Machine taken, or want some variety? These work the same main muscles.
Single-arm Preacher Curl FAQs
What weight should I use for single-arm preacher curls?
Start with a light dumbbell that lets you complete 10-12 smooth reps with your upper arm staying on the pad. Preacher curls are stricter than standard curls, so most people use less weight than usual. Increase by the smallest step available once you can complete every set with good form.
Why do preacher curls feel hard at the bottom?
The pad holds your upper arm in place, so the biceps are working hard at the stretched bottom position where you can't cheat. Lower the weight and control the descent, and don't force your elbow into a locked-out position. If you feel pain rather than muscle effort, stop and get it checked.
Can I do a single-arm preacher curl without a preacher bench?
Yes. You can rest the back of your upper arm on the top of an incline bench set to a steep angle, or use a sturdy angled pad in the gym. The aim is the same: a stable surface that keeps your upper arm still while your elbow bends.
Track your Single-arm Preacher Curl progress
GymTracker builds your plan, pre-fills the weight from last time and tells you when to go up. Free.
Start free