The triceps brachii muscle, commonly called the triceps, is the largest muscle in the upper arm, constituting approximately two-thirds of the arm’s total muscle mass. This muscle group is composed of three distinct heads, which must be trained comprehensively for complete and balanced arm development. Understanding the anatomy and function of each head allows for a strategic approach to exercise selection. The goal is to ensure all three parts receive adequate tension to stimulate growth.
Understanding the Three Triceps Heads
The three heads of the triceps brachii are the long, lateral, and medial heads, each originating from a different point on the arm skeleton. All three heads converge into a single tendon that inserts onto the olecranon process of the ulna at the tip of the elbow. Their shared primary function is the extension of the elbow joint, which means straightening the arm.
The lateral head originates from the humerus, superior to the radial groove, and contributes to the horseshoe shape visible on the outside of the arm. The medial head also originates from the humerus, inferior to the radial groove, and lies mostly underneath the other two heads, helping stabilize the elbow.
The long head is unique because it originates from the scapula (shoulder blade), making it the only head that crosses both the elbow and the shoulder joints. Because it crosses the shoulder joint, it assists in the extension and adduction of the arm, helping pull the arm backward or toward the body. This dual attachment means the long head’s recruitment depends heavily on the arm’s position relative to the torso. The lateral and medial heads are primarily limited to elbow extension.
Exercises for the Long Head
To fully engage the long head, exercises must incorporate shoulder flexion, which places the muscle in a stretched position. This positioning maximizes the mechanical tension felt by the long head fibers throughout the movement. Movements that involve raising the arms overhead, positioning the elbow close to the ear, are most effective.
The Overhead Dumbbell Extension is a prime example, where the weight is lowered behind the head with the biceps positioned next to the ears. This movement stretches the long head across the shoulder joint while requiring elbow extension against resistance. Cable Overhead Triceps Extensions, performed facing away from the machine, offer constant tension and enhance the stimulus for growth.
Lying Triceps Extensions, often called Skull Crushers, also effectively target the long head, especially when the upper arms are positioned slightly behind the head. Allowing the bar to travel toward the bench behind the head, rather than directly over the forehead, ensures a greater stretch. Exercises like the close-grip bench press also activate the long head significantly, particularly when keeping the elbows tucked.
Targeting the Lateral and Medial Heads
The lateral and medial heads are best recruited through movements where the arm is kept close to the body, eliminating the stretch component that favors the long head. The lateral head contributes significantly to the width and definition of the arm. It is strongly activated during standard Triceps Pushdowns using a straight bar or V-bar attachment, which allows for heavy loading focused on elbow extension.
The Medial head is considered the workhorse of the triceps, often highly active in most elbow extension movements for stability. To specifically emphasize the medial head, subtle variations in grip and forearm position are employed. Performing the Reverse-Grip Triceps Pushdown (supinated grip) shifts activation away from the lateral head and increases focus on the medial head.
Compound movements like the Close-Grip Bench Press are also highly effective for engaging the medial head, particularly in the final phase of elbow extension. Narrowing the grip shifts the load from the chest and shoulders to the triceps. The medial head is often highly active in exercises performed for higher repetitions, such as cable pushdowns or dips.
Structuring a Complete Triceps Workout
A comprehensive triceps workout should prioritize hitting all three heads by selecting one exercise for each distinct function. A logical structure begins with an exercise that allows for heavy loading, followed by two isolation movements targeting the remaining heads. Starting with a compound movement like the Close-Grip Bench Press allows for the use of heavier weights, stimulating overall triceps growth while heavily engaging the medial head.
Following the compound lift, a movement that places the long head under stretch is beneficial, such as the Overhead Dumbbell Extension. This exercise should be performed with a controlled tempo, emphasizing the deep stretch at the bottom. The final exercise should focus on the lateral head, using a standard Cable Pushdown or a similar variation where the arms are kept at the side.
Repetition and Volume
For hypertrophy, a set and rep scheme typically involves 3 to 4 sets per exercise, with 8 to 12 repetitions being optimal for muscle growth. Incorporating a variety of rep ranges, such as a heavy set of 5 to 10 reps and a lighter set of 15 to 20 reps, can promote comprehensive development. Triceps can be trained directly one to two times per week, depending on the volume of chest and shoulder pressing movements already present.