The biceps brachii is the muscle group on the front of the upper arm, and it is composed of two distinct sections, commonly referred to as heads: the long head and the short head. Developing both is necessary for a full, well-defined arm. The goal of “hitting the outside bicep” refers specifically to targeting the long head, which contributes to the muscle’s peak and overall shape. Strategic exercise selection and precise technique adjustments can shift the workload to emphasize this outer portion of the muscle.
Understanding the Bicep’s Outer Head
The biceps brachii is a two-headed muscle; the long head is often referred to as the “outside bicep.” It originates from the supraglenoid tubercle on the scapula (shoulder blade), giving it a unique path that crosses the shoulder joint. This anatomical difference is the primary reason certain movements can preferentially load this head.
The long head’s tendon travels through the shoulder joint capsule before joining the short head to insert onto the radius bone in the forearm. Because of its attachment point on the shoulder blade, the long head is placed under a significant stretch when the arm is positioned behind the body. This pre-stretching increases muscle fiber recruitment and is a fundamental principle for emphasizing the long head during a curl.
Movements that involve shoulder extension, where the elbow is behind the torso, place a mechanical advantage on the long head. Additionally, a narrower grip width tends to position the arm in a way that favors the long head’s line of pull. While complete isolation of one head is not possible, these biomechanical factors allow for greater emphasis on the long head during specific exercises.
Targeted Exercises for Long Head Activation
One of the most effective movements for the long head is the Incline Dumbbell Curl, performed while seated on a bench set to a 45- to 60-degree angle. In this position, the arms hang down behind the torso, placing the long head under a significant stretch at the start of the movement. The lengthened position increases the activation of the long head throughout the curl, making it a powerful tool for developing the bicep peak.
The Drag Curl is another exercise that specifically targets the long head by altering the elbow position. Instead of keeping the elbows fixed in front, the drag curl requires the lifter to pull the weight up while simultaneously driving the elbows backward. This action ensures the long head is under constant tension and prevents the involvement of the front shoulder muscles, which often take over in standard curls.
Close-Grip Barbell Curls or EZ-Bar Curls also shift the emphasis toward the long head. By using a grip that is narrower than shoulder-width, the angle of the forearm places more tension on the outer bicep fibers, forcing the long head to perform more of the work compared to a wider grip. This narrow hand placement, combined with keeping the elbows tight to the sides, is highly effective for heavy loading and consistent tension.
Technique Adjustments for Isolation
Maximizing the workload on the long head requires deliberate adjustments to standard curling mechanics. A narrower grip width is a consistent cue that optimizes the long head’s line of pull; positioning the hands closer together on a barbell or cable attachment naturally favors the outer bicep.
Controlling the position of the elbow is another adjustment that directly influences long head activation. For exercises where the arm is not already extended, pulling the elbows slightly back behind the line of the torso during the curl can pre-stretch the long head and increase its involvement. The goal is to maintain this fixed elbow position throughout the movement, using the biceps to move the weight rather than momentum.
Using a neutral grip, or hammer grip, where the palms face each other, also helps to emphasize the long head and the underlying brachialis muscle. This grip prevents the full supination of the forearm, which typically engages the short head more prominently.
Focusing on a slow, controlled negative phase of the lift is another technique adjustment. This ensures the long head receives extended time under tension, which is known to promote muscle growth.