As its name indicates, the triceps muscle group consists of three muscles: the lateral head is considered the outer triceps, the medial head is in the middle, while the long head is the innermost of the triceps group. All three heads help your elbows extend, but the inner triceps also contributes to some shoulder movements. Your triceps account for about two-thirds of your upper arm’s mass, so you need to work all three triceps heads to reach your maximum arm strength potential.
Perform a one-arm dumbbell triceps extension by standing erect with your feet about shoulder-width apart and holding a dumbbell in one hand. Assume the starting position by extending your arm and raising the dumbbell straight over your head, with your palm facing forward and your pinkie higher than your other fingers. Inhale as you lower the dumbbell behind your head, moving your forearm alone, until your forearm is roughly parallel with the floor. Exhale as you raise the weight to the starting position.
Find a dip machine or a pair of adjustable dip bars and set the bars at a wide spacing, which focuses more resistance on the inner triceps. Grip the bars with your thumbs facing forward, then lift yourself until your arms are straight. This is your starting position. Inhale as you bend your elbows to lower your body, while your forearms remain perpendicular to the floor. Exhale as you lift yourself back to the starting position. Keep your torso straight at all times.
Sit on a bench or chair and hold a barbell straight over your head to do a triceps press. Use an overhand grip and spread your hands wider than shoulder-width to emphasize your inner triceps. Begin with your arms extended, then inhale, flex your elbows and lower the bar behind your head. Exhale as you raise the barbell to the starting position. Move your upper arms as little as possible.
Tips
The one-arm triceps extension can also be performed while you’re seated. You can make triceps dips more challenging by wearing a weighted belt.
Use enough weight to fatigue your arms within 90 seconds when you’re performing the free-weight exercises. Perform fewer repetitions and choose heavier weights to add strength, or select lighter weights and do more reps to improve your muscular endurance.
Warnings
Use a spotter when you’re lifting weights over your head. Don’t do the triceps press if you have elbow or shoulder pain.