Hammer curls are one of the most popular bicep exercises, and for good reasons. They are relatively easy to learn, provide a decent overload, and train the biceps and forearms together.
Read on to learn what makes the movement special, how to perform it safely, and what mistakes to watch out for.
Table of Contents
What Are Hammer Curls?
Hammer curls are an isolation exercise based on elbow flexion (arm bending). They primarily target the biceps brachii but also work the brachialis (a muscle underneath the bicep) and brachioradialis (a forearm muscle involved in elbow flexion).
The primary difference between hammer and regular curls is wrist position. During a standard curl, the palms face forward and up at the top of each rep.
In contrast, trainees must maintain a neutral wrist position (palms facing one another) from start to finish during a hammer curl.
While subtle, that’s enough of a difference to make hammer curls an exercise worth doing alongside regular curls. We’ll discuss the unique benefits below.
Primary Muscles Worked 💪
- Biceps (Brachii & Brachialis)
Secondary Muscles Worked 💪
- Forearms (Brachioradialis)
How to Perform Hammer Curls (Step-By-Step)
Things to keep in mind:
- Elbows glued to your sides
- Shoulders back
- Wrists neutral from start to finish
- Glutes and abs squeezed
- Squeeze the biceps at the top of each rep
Performing Hammer Curls
- Grab a pair of dumbbells and stand tall.
- Position your arms to your sides with your palms facing your body.
- Retract your shoulder blades, squeeze your glutes, take a deep breath, and engage your abs.
- Slowly bend your arms as you curl the weights to the up position until your wrists are slightly higher than your elbows. Keep your elbows to your sides, and don’t move them forward as you bend your arms.
- Pause briefly at the top, squeezing your biceps.
- Slowly extend your arms as you exhale back to the start position.
The Benefits of Hammer Curls
1. Brachialis Growth
Hammer curls do a fantastic job of targeting the brachialis muscle. It lies underneath the bicep and pushes it out more as it develops. As a result, the biceps appear larger and with a more prominent peak when the muscle is properly developed.
2. Slightly Better Overload
Due to the neutral wrist position, most trainees find it easier to curl a bit more weight with proper form. This could help create a stronger stimulus, promote strength gains, and improve bicep growth. By neutral position, we mean the angle of resistance does not create additional pressure on the joint (like wide-grip barbell curls do).
3. Wrist and Elbow Comfort
For some people, a neutral wrist position feels more comfortable and alleviates nagging aches resulting from pronated or supinated wrist positions. (1)
4. Plenty of Variations to Pick From
Another benefit of hammer curls is that you can tweak the movement and pick from several variations to keep your bicep training novel and enjoyable. Let’s look at some potential tweaks now.
Tweaks and Variations of the Hammer Curl
1. Seated Hammer Curl
Performing the exercise from a seated position reduces the risk of using momentum, allowing you to feel more tension in your biceps.
Consider this variation if you often swing back and forth or use too much momentum.
2. Cross-Body Hammer Curl
This is a variation where you maintain a neutral wrist position. However, you lift the weights diagonally across your torso instead of keeping the weights to your sides.
3. Alternating Hammer Curl
Instead of curling both dumbbells together, you do so one at a time in an alternating fashion. Doing so can be a nice way to give each arm a ‘mini-break’ between reps, potentially allowing you to do slightly more reps per set.
4. Incline Hammer Curl
This is a variation where you set the incline of a bench at 60-70 degrees (almost upright), sit back, and perform regular or alternating hammer curls.
The advantage of this position is that it places a greater stretch on your biceps, potentially resulting in a stronger growth response.
5. Hammer Curl to Overhead Press
This is a more complex variation where the goal is to transition from a curl to an overhead press (with a neutral grip), thus training the biceps, shoulders, triceps, and upper chest in one sequence.
It goes like this:
Curl ⇒ Overhead press ⇒ Lower the dumbbells to your sides ⇒ Curl ⇒ Continue the sequence
6. Hammer Curl 21s
With this variation, the goal is to do the first half of the curl for seven reps, then the second half for another seven reps, and finish with seven full reps.
Safety Tips and Final Considerations
Hammer curls are relatively safe because the movement pattern is simple, and trainees can’t use that much weight.
That said, trainees should always prepare themselves with a good warm-up consisting of some light cardio, dynamic stretching (elbow rotations, wrist twists, arm swings, etc.), and a couple of bicep curl sets with less weight for fewer reps. (2)
Additionally, perform reps with proper form and always control the dumbbells. Don’t allow the weights to drop to the bottom because that can strain the elbows and biceps, leading to aches.
- HW;, K. M. C. Y. (n.d.). Static wrist position associated with least median nerve compression: Sonographic evaluation. American journal of physical medicine & rehabilitation.https://pubmed.ncbi.nlm.nih.gov/11277131/
- Elizabeth Quinn, M. S. (2020, March 13). Prevent injuries. Verywell Fit.