The Resistance Band Hammer Curl (RB Hammer Curl) is one of the best arm exercises you can do at home to build thicker biceps and stronger forearms. Thanks to the neutral grip, it targets the brachialis and brachioradialis while still hitting the biceps — giving your upper arms that dense, athletic look.
In this guide, you’ll learn exactly how to perform the RB Hammer Curl, which muscles it works, the best sets and reps, plus the most common mistakes to avoid so your elbows stay happy.
RB Hammer Curl Tutorial Video
Follow along with the full technique breakdown in this video:
What Is the RB Hammer Curl?
The RB Hammer Curl is a hammer curl performed with a resistance band instead of dumbbells. You hold the band in a neutral grip (palms facing each other) and curl your hands toward your shoulders.
This grip shifts more tension to the brachialis and forearms while still working the biceps. The band provides increasing resistance as you curl up, making the top of the movement especially challenging.
Which Muscles Does the RB Hammer Curl Work?
The RB Hammer Curl primarily targets the muscles of the upper arm and forearm:
- Brachialis (main target)
- Biceps brachii (especially the long head)
- Brachioradialis (forearm)
- Other forearm flexors
- Grip muscles (holding the band)
- Core and upper back (stabilisation)
Because it emphasises the brachialis, the RB Hammer Curl can make your upper arm appear thicker even when viewed from the front.
How to Do the RB Hammer Curl: Step-by-Step
1. Set up the band
- Place the middle of the resistance band under your feet. Start with feet about hip-width apart.
- Hold the ends or handles of the band with a neutral grip (palms facing each other).
- Stand tall with your chest gently lifted, shoulders down and back, and core engaged.
2. Find the starting position
- Arms hang straight by your sides with a soft bend at the elbow, not locked.
- Elbows stay close to your ribs throughout the movement.
- There should already be a bit of tension in the band at the bottom.
3. Curl the band
- Take a breath in to brace your core.
- As you exhale, curl your hands up toward your shoulders, keeping your palms facing each other.
- Focus on bending at the elbows only; don’t swing your shoulders or hips.
- Stop when your hands are just below shoulder height and squeeze your biceps and brachialis for 1 second.
4. Lower with control
- Slowly lower your hands back down to the starting position over 2–3 seconds.
- Keep tension in the band at the bottom; don’t let your arms fully relax.
- Repeat for the desired number of reps.
Think “elbows stay pinned to my sides”. If your elbows drift forward, you lose tension on the biceps and start turning the movement into a shoulder exercise.
Breathing, Tempo & Ideal Reps
- Breathing: Inhale before you curl, exhale as you bring the band up, then breathe steadily as you lower.
- Tempo: 1 second up – 1 second squeeze – 2–3 seconds down.
- Reps: 8–15 reps per set works well for muscle growth and strength.
- Sets: Aim for 3–4 sets in your arm or pull workout.
- Frequency: 1–2 times per week, depending on your overall training volume.
Common RB Hammer Curl Mistakes (and How to Fix Them)
1. Swinging the body
Using your hips and lower back to throw the band up takes tension away from your arms and increases injury risk. Choose a band that allows you to curl with control, not momentum.
2. Elbows drifting forward
When your elbows move in front of your body, the biceps get a break and your shoulders take over. Keep your elbows tucked by your sides like they are glued in place.
3. Curling only halfway
Short, half-reps limit muscle activation. Make sure you fully curl up (without letting the shoulders roll forward) and fully extend at the bottom while maintaining slight tension in the band.
4. Using a band that is too heavy
With resistance bands, “heavier” doesn’t always mean better. If you can’t control the top or your wrists bend awkwardly, drop to a lighter band and prioritise clean technique.
Who Should Use the RB Hammer Curl?
The RB Hammer Curl is a great fit if you:
- Train at home or while travelling and want a compact arm workout.
- Need a more joint-friendly option than heavy dumbbells.
- Want bigger, thicker upper arms and stronger forearms.
If you have a history of elbow or wrist pain, start with a lighter band and a comfortable range of motion. If discomfort persists, consult a qualified professional.
RB Hammer Curl Variations
- Single-arm RB Hammer Curl: Great for fixing side-to-side imbalances and improving core stability.
- Alternating RB Hammer Curl: Curl one arm at a time to keep tension without over-fatiguing both arms at once.
- Kneeling RB Hammer Curl: Reduces lower-body involvement and makes it easier to keep your torso still.
- High-rep finisher: Use a light band for 15–25 reps as a pump-style finisher at the end of your arm workout.
FAQ: RB Hammer Curl
How many sets and reps should I do for the RB Hammer Curl?
A solid starting point is 3–4 sets of 8–15 reps. Choose a band that lets you feel a strong burn in the last few reps without needing to swing or cheat.
Is the Resistance Band Hammer Curl good for building biceps size?
Yes. Because it targets both the biceps and brachialis, the RB Hammer Curl is excellent for building overall arm thickness. Combine it with standard curls and heavy pulling movements for best results.
Can beginners do the RB Hammer Curl?
Absolutely. Beginners can start with a light band, focus on slow and controlled reps, and limit total volume to 2–3 sets. As technique improves, they can increase sets, reps, or resistance.
Where should I place the RB Hammer Curl in my workout?
Most people will benefit from doing RB Hammer Curls towards the end of a pull or arm workout, after compound exercises like rows and pull-ups. This way, you save isolation work for when your big lifts are done.
What if I feel the RB Hammer Curl more in my wrists than my biceps?
If your wrists hurt, you may be using a band that’s too heavy or letting them bend excessively. Switch to a lighter band, keep a neutral wrist position, and focus on moving only at the elbow joint.
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