Exercise Overview
The hammer curl is performed holding dumbbells with a neutral grip (palms facing each other), curling the weight up while maintaining that grip throughout. The neutral position shifts emphasis away from the biceps brachii and onto the brachialis and brachioradialis.
The barbell curl is performed with a supinated grip (palms facing up) on a straight barbell or EZ bar, curling the weight from a hang position to full elbow flexion. This grip more directly targets the biceps brachii.
Neither exercise has a dedicated guide on this site yet — both are commonly programmed as biceps and forearm accessories alongside back and pulling exercises.
Muscles Worked
Hammer curl primarily targets the brachialis and brachioradialis (a forearm muscle), with the biceps brachii assisting. Barbell curl primarily targets the biceps brachii, with the brachialis assisting. Both muscles contribute to overall arm size, so training both grip positions leads to more complete arm development.
Strength Development
Barbell curl generally allows heavier total loading since a single barbell trains both arms bilaterally with a mechanically efficient grip. Hammer curl is limited by dumbbell availability and the neutral grip position, but still builds meaningful forearm and brachialis strength that supports grip-dependent activities.
Muscle Growth
Both contribute to arm size in different ways. Barbell curl builds the biceps brachii, contributing to the visible “peak” many lifters associate with bigger arms. Hammer curl builds the brachialis (which pushes the biceps up, adding to arm thickness) and the forearms, contributing to overall arm size from a different angle.
Beginner Friendliness
Both are straightforward, beginner-friendly exercises with a low technical skill requirement. Hammer curl’s neutral grip is often slightly more comfortable initially for lifters with wrist or elbow sensitivity.
Safety
Both are low-risk exercises when performed with reasonable loading and controlled form. Barbell curl’s fully supinated grip can occasionally cause wrist discomfort for some lifters, in which case an EZ bar (with an angled grip) or switching to hammer curls is a practical solution.
Programming
Use both as biceps and forearm accessories in the 8-15 rep range, 1-3 times per week as part of a broader arm or pull-focused training day. They pair well as a superset or performed back-to-back within the same workout.
Common Mistakes
Hammer curl mistakes: using momentum to swing the dumbbells up, and not controlling the eccentric (lowering) phase. Fix these by keeping the elbows fixed at the sides and lowering the weight slowly and under control.
Barbell curl mistakes: using body momentum (“curl swinging”) and not achieving a full range of motion. Fix these by keeping the elbows fixed at the sides and controlling the weight through the complete curl and lowering phase.
