Hammer Curl — Build Brachialis and Forearm for Complete Arm Thickness

Hammer Curl: Building Arm Thickness Through Brachialis Development#

The hammer curl is the most underutilized curl variation for developing upper arm thickness. While standard curls primarily target the bicep brachii, hammer curls emphasize the brachialis (a muscle underneath the bicep) and brachioradialis (a forearm muscle). When the brachialis develops, it pushes the overlying bicep upward — increasing the arm's peak and creating the thick, complete arm appearance.

The Neutral Grip: What It Changes#

The hammer curl uses a neutral grip (thumbs facing upward) throughout — no supination occurs. This grip position:

• Reduces the bicep brachii's mechanical advantage (the bicep is most effective in a supinated position)
• Transfers more of the loading to the brachialis (which is not significantly affected by supination/pronation)
• Involves the brachioradialis heavily (a muscle that runs along the outer forearm)

The practical result: hammer curls feel different from standard curls, working the arm in a complementary pattern.

Standard Hammer Curl Technique#

Grip: Neutral — thumbs pointing upward, palms facing each other. Maintain this neutral grip throughout the entire movement (unlike supinating curls).

Execution: Curl upward from the extended position, maintaining the neutral grip. The dumbbells rise like hammers — hence the name.

Elbow position: Same as standard curls — fixed at the sides, no forward drift.

Range: Full extension at the bottom, full flexion at the top with a deliberate squeeze.

Cross-Body Hammer Curl Variation#

The cross-body hammer curl adds a horizontal component:

Execution: Instead of curling the dumbbell straight up, curl it across the body — toward the opposite shoulder. This cross-body path changes the moment arm and increases brachialis activation.

Alternate sides on each repetition — or perform all reps on one side before switching.

Programming Hammer Curls#

In combination with standard curls: One set of supinating curls, one set of hammer curls, alternating. This trains both the bicep brachii (supinating) and the brachialis (neutral) systematically.

After standard curls: 3 × 10–15 hammer curls as an additional curl variation.

FAQs: Hammer Curls#

Q: Hammer curl vs regular curl — which builds bigger arms? A: Different muscles, both necessary. Standard supinating curls primarily develop the bicep brachii. Hammer curls primarily develop the brachialis and brachioradialis. Complete arm development requires both — the brachialis's size pushes the bicep up, creating the thick, impressive arm appearance that bicep curls alone don't produce.

Q: Can hammer curls replace regular bicep curls? A: No — they should complement, not replace. The supinating standard curl targets the bicep brachii most effectively; the hammer curl targets the brachialis and brachioradialis most effectively. A complete arm program includes both.

---

ARMS POST 7#

---

Analyze Your Arms Form with AI — Free#

SportsReflector uses computer vision to score your technique across every gym exercise and 20+ sports. Get instant feedback on form, symmetry, and injury risk — directly from your iPhone.

View on App Store