Both bicep curls and hammer curls should be part of an arm training routine. While both exercises involve elbow flexion, they utilize fundamentally different grip positions that strategically target distinct muscle groups within the arm. Relying on only one type of curl results in incomplete development of the entire upper arm and forearm complex. Combining the two movements is the most effective strategy for achieving comprehensive arm strength and size.
Focus and Mechanics of the Bicep Curl
The traditional bicep curl is performed using a supinated grip, which means the palms face upward or forward throughout the movement. This specific hand orientation maximizes the contraction of the Biceps Brachii, the large, two-headed muscle on the front of the upper arm. The supinated grip is particularly effective at targeting the short head of the biceps, which is the primary contributor to the visible “peak” of the muscle when flexed.
Proper execution involves pinning the elbows close to the sides of the torso to isolate the movement at the elbow joint. The weight is curled upward with a focus on squeezing the biceps hard at the top of the range of motion. Maintaining a stable core and avoiding the use of momentum is necessary to ensure the Biceps Brachii handles the majority of the load.
Focus and Mechanics of the Hammer Curl
The hammer curl employs a neutral grip, where the palms face each other, similar to holding a hammer. This change in grip shifts the mechanical advantage and places emphasis on two muscles often underdeveloped by standard supinated curls. The primary target of the hammer curl is the Brachialis, a powerful elbow flexor that lies beneath the Biceps Brachii.
Development of the Brachialis is important because as it grows, it pushes the Biceps Brachii upward, contributing to overall arm girth and thickness. The neutral grip also heavily recruits the Brachioradialis, which is one of the largest muscles of the forearm, running along the thumb side of the arm. Performing the hammer curl correctly involves keeping the neutral grip rigid and lifting the weight directly upward, ensuring the work is distributed across the Brachialis and Brachioradialis.
Integrating Both for Comprehensive Arm Development
Incorporating both the supinated bicep curl and the neutral grip hammer curl is the optimal strategy for maximizing arm development. The two exercises create a synergistic effect, where the bicep curl focuses on the height and peak of the arm, and the hammer curl contributes to the width and thickness. Training only one aspect will result in an incomplete arm.
A balanced approach involves alternating these movements within the same workout session or dedicating separate days to each. For example, a workout might begin with the supinated curl to pre-fatigue the Biceps Brachii, followed by the hammer curl to recruit the Brachialis and Brachioradialis. Using a variety of set and repetition schemes is also beneficial. Perform the bicep curl for moderate repetitions (8–12) to maximize the peak contraction, then move to the hammer curl with slightly heavier weights for strength and thickness.
The mechanical difference in grip angle ensures all major arm flexors are targeted, which is crucial for balanced strength development around the elbow joint. The Biceps Brachii is responsible for both elbow flexion and forearm supination, while the Brachialis is considered the strongest elbow flexor, regardless of forearm position. Systematically addressing both functions ensures holistic growth that translates to improved performance in other pulling movements and greater overall arm size.