Hammer curl angled to crush the brachialis.
Keep your elbow pinned to your side as you curl across. Don't let it drift out.
Curling a neutral-grip dumbbell across your body toward the opposite shoulder biases the brachialis, the muscle under the biceps that pushes the whole upper arm out wider when it grows. The cross-body path keeps your palm facing in throughout, holding the load on that thickness-building line for the entire rep. It slots in after your main curl as the arm-width move most programmes forget.
The path. A standard hammer curl travels straight up, while the cross-body version arcs the dumbbell toward the opposite shoulder, which many lifters find keeps tension on the brachialis better and stops the elbow drifting.
They target the muscle that sits underneath the biceps, which pushes the whole arm out wider as it develops. Pair them with a palms-up curl and you cover both shape and size.
The setup here alternates arms, which gives each side a brief rest and keeps form crisp. Just do not use the alternation as an excuse to rock your torso between reps.
