- Biceps: Arm flexor
(Musculus biceps brachii)
- Biceps: Arm flexor short head
(Musculus biceps brachii, Caput breve)
- Biceps: Arm flexor long head
(Musculus biceps brachii, Caput longum)
- Upper arm: Coracobrachialis muscle
Hammer Curls: Basics and alternatives
Involved main muscle groups:
Hammer curls are a variation of biceps curls with a different grip. In this exercise, you hold the dumbbells with a neutral grip throughout the entire movement. The motion is essentially the same: You lift the dumbbells from the sides of your body upwards by bending your elbows.
The focus of hammer curls is on the upper arms, targeting the biceps (musculus biceps brachii) and the upper arm muscle (musculus brachialis). It’s a classic isolation exercise.
As an alternative compound exercise that activates the upper arm similarly, you can perform hammer grip pull-ups. Although these mainly focus on the back muscles, the biceps are also heavily involved due to the grip technique. Hammer grip pull-ups are often included in workout routines on the same day as biceps training.
Don’t confuse this exercise with hammer grip wrist curls, which focus on the forearm rather than the upper arm.
You can perform hammer curls simultaneously or alternately. Typically, simultaneous execution is preferred because it helps maintain a more stable upper body posture.
When alternating, the dumbbells are lifted one at a time rather than both at once. This has the advantage of a slightly longer break between repetitions, which can help you complete 1-2 more reps. The downside, especially with heavier weights, is that it’s harder to stabilize your upper body, which may result in an unbalanced movement. Make sure to maintain proper form, especially when alternating.
Grab the dumbbells and stand with your feet hip-width apart. Hold the dumbbells at your sides with a neutral grip (palms facing each other).
Bend your elbows and raise both dumbbells at the same time. Keep your palms facing each other throughout the movement, without rotating them.
When your elbows are bent, you’ve reached the end of the movement. Hold the tension for a moment.
Lower the dumbbells slowly and with control, keeping your palms in the same position. At the end, your arms are fully extended, and the dumbbells are beside your body.
A classic mistake in biceps curls, including hammer curls, is using momentum. Keep your upper body straight and your core engaged throughout the exercise. Avoid leaning back or swinging your arm to move the weight forward or up with momentum. This significantly reduces the training effect. Ensure the movement is primarily achieved by bending your elbows.