FormTwin › Exercises › Hammer Curl

What muscles does the Hammer Curl work?

The hammer curl builds arm thickness by training the brachialis and forearms alongside the biceps, using a neutral (palms-in) grip.

Primary muscles worked

Secondary muscles worked

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How to do the Hammer Curl

  1. Hold dumbbells with palms facing each other.
  2. Keep your elbows pinned to your sides.
  3. Curl the weights up without rotating your wrists.
  4. Squeeze, then lower slowly under control.

Common mistakes

Variations

Cross-body hammer curlRope hammer curlStandard bicep curl

Frequently asked questions

What muscles do hammer curls work?

Hammer curls train the brachialis (which sits under the biceps and pushes them up), the biceps, and the brachioradialis of the forearm. That's why they add thickness to the whole arm.

Hammer curl vs bicep curl?

A standard curl (palms up) emphasises the biceps peak; the hammer curl (palms in) shifts load onto the brachialis and forearms and often lets you lift a little heavier. Both belong in an arm routine.

Do hammer curls work forearms?

Yes — the neutral grip strongly recruits the brachioradialis, one of the main forearm muscles, making hammer curls a two-for-one for arm size.

Related exercises

DeadliftBack SquatBench PressPull-UpPush-Up

This guide is general fitness information, not medical advice. Muscle involvement varies with form, grip and individual anatomy. Consult a professional before starting a new program.