The triceps brachii is comprised of three distinct heads: the medial, long and lateral head. The lateral head is found on the outside border of the upper arm and is primarily responsible for the horseshoe shape of the triceps. Working to failure on each set of specific exercises can target strength and tone in the alteral head of the tricep.
Pushdowns target all three heads of the triceps, but using a rope attachment further isolates the lateral head. Stand facing a high-pulley machine. Grasp an end of the rope attachment in each hand. Begin with your elbows bent and tucked in close to your body and your fists close to your chest. With your back straight and your core muscles engaged, push down on the cable by extending your arms until your hands touch the front of your thighs. Pause here then slowly return to the starting position and repeat.
One-arm Reverse Pushdown
This exercise mainly works the lateral head of the triceps. Stand facing a high-cable machine and grasp the handle with an underhand grip. Begin with your hand at chest-level, elbow bent and tucked close to your side. Pull the cable down by extending your elbow. Pause here, squeezing your triceps, then slowly return to the starting position. Complete the desired number of repetitions then repeat the exercise with the opposite arm.
E-Z Bar Triceps Extensions
The overhand grip used during this triceps exercise isolates the lateral head of the muscle. Sit or stand with your back straight and your abdomen muscles engaged. Grasp an E-Z bar with an overhand grip and extend your arms vertically above your head. From this position, bend your elbows to lower the bar behind your head. Contract your triceps to extend your arms and return to the starting position.
Dumbbell Triceps Extension
The dumbbell extension works not only the lateral head of the triceps but the medial and long heads as well. Lie on a flat bench with your knees bent and feet flat on the floor. Hold a dumbbell in each hand with your palms facing each other and your arms extended vertically above your chest. Bend your elbows to lower your forearms in a controlled manner until they reach 90-degree angles. Lift the weights back to the starting position by extending your arms.