When your neighbor’s kid tells you to make a muscle, you’ll almost certainly flex your biceps — that flashy mountain of muscle on the inside of your upper arm. But if it’s impressive arm size you’re looking for, it’s the muscles on the back of your arm — the less-appreciated triceps — that should get most of your attention in your workouts.
Here’s why: The triceps have nearly twice the muscle tissue of the biceps, so they have more potential for growth than their famous relatives on the opposing side of the upper arm. As that “tri” prefix suggests, the triceps consist of three segments, or heads. When defined and developed, these three muscles form a distinctive inverted “V” that runs from the back of your shoulder to your elbow along the back of your arm.
Horseshoe triceps are one of those “tells” that make it clear that you put in the hours in the gym. They’re visible whenever you wear tank tops or short sleeves — one of those little beacons that declares, “Yup — I work out.”
The triceps are active any time you straighten your elbow. “The incline press, flat bench press, and overhead press all work the triceps in almost exactly the same way,” says muscle-building expert Bret Contreras, PhD, CSCS, author of Strong Curves. So if you’re short on time, any chest or shoulder-based move where you press a weight away from you with your arms will also work your triceps to some degree.
For maximal development, though, most people need direct triceps exercises. Here are a few of our favorites to build horseshoe triceps.
6 Moves to Help You Get Horseshoe Triceps
For best development of those horseshoe muscles, choose a variety of exercises where the upper arm is in a different position relative to your trunk: overhead, behind you, and in front of you.
1. Dumbbell overhead triceps extension
- Hold a single dumbbell overhead with the handle vertical, palms on the inside edge of the top set of plates, thumbs and index fingers encircling the handle for safety.
- Keeping your elbows close to your ears, your face forward and your neck upright, bend your arms until you feel a deep stretch in your triceps.
- Pause for a moment and reverse the move, returning to the starting position.
2. Lying triceps extension (skullcrusher)
- Lie face up on a bench with your feet flat on the floor, and hold a pair of dumbbells above your chest with your arms straight and your palms facing each other.
- Without moving your upper arms, bend your elbows and lower the dumbbells to the sides of your head until your forearms dip below parallel to the floor.
- Pause, and then return to the starting position.
3. Triceps pushdown
- Stand facing a triceps machine with a rope attachment, and take hold of the ropes with a neutral (palms facing) grip.
- Lock your elbows into your sides, and keep them there throughout the movement.
- Slowly extend your arms, spreading your hands apart as far as possible at the bottom of the movement.
- Pause for a moment, contracting your triceps as hard as possible.
- Keeping your elbows by your sides, slowly bend your arms fully and return to the starting position. Repeat for reps.
4. Dumbbell triceps kickback
- Stand holding two light dumbbells by your sides.
- Keeping your lower back slightly arched, and your chest forward and up, bend your knees slightly and hinge forward at your hip joints until your trunk is nearly parallel to the floor.
- Bend your arms and lock your elbows to your sides (this is your starting position).
- Slowly straighten your arms, contracting the backs of your arms as hard as possible at the top of the move. Allow your upper arms to move upward — toward the ceiling — at the top of this exercise.
- Pause with your triceps fully engaged.
- Slowly reverse the move and return to the starting position.
5. Triceps dip
- Jump into the support position on a set of dipping bars: feet off the floor, shoulders down, elbows locked out, posture vertical.
- Slowly bend your arms and lower yourself until your upper arms are parallel to the floor.
- Pause for a moment, return to the starting position, and repeat for reps.
6. Banded triceps kickback
- Secure one end of a resistance tube with handles to a stationary object about six inches off the floor (the leg of a couch works well).
- Holding the free end of the band in your right hand, hinge forward at your hips until your torso is roughly parallel to the floor, and tuck your right elbow to your side.
- Step forward or backward so that there’s light tension in the band. This is your starting position.
- Keeping your right elbow pinned to your side, extend your right hand behind you.
- Squeeze your right triceps as hard as possible for a one-count, and then slowly return to the starting position.
- Perform equal reps with each arm.
How to Start Tricking Out Your Tris
Though they all work together to straighten your arm, the three heads of your triceps have distinct forms and functions:
Long head
The long head runs from the outside corner of your shoulder blade (near where your upper arm connects to your shoulder) down the back of your upper arm to your elbow, where it attaches near your funny bone.
If you stand with your arms hanging down, the long head is the section of the muscle closest to your side. Because it attaches to your shoulder blade, the long head assists in the action of pushing your upper arm backward and behind you (picture pushing yourself forward with ski poles).
Medial head
The medial head runs from the back of your upper arm, close to your shoulder joint, down to your elbow. Parts of the medial head are obscured by the other two heads, but you can see and feel the sheet-like lower portion of the muscle just above the middle of your elbow on the back of your arm.
Lateral head
The lateral head runs from the bony bump on the back of your shoulder downward along the outside of the back of your arm, to your elbow — again, near the funny bone. When it’s developed and well-defined, the lateral head forms a distinctive croissant or prawn shape.
How to target each head
Since the medial and lateral heads don’t cross the shoulder joint, only the long head is involved in the articulation of your upper arm relative to your trunk. The other two heads only extend your elbow.
That’s important when choosing triceps exercises: When you extend your upper arm overhead and keep it there as you bend your elbow, the long head stretches significantly more — and thus works significantly harder — than it does if your arm is by your side.
Conversely, when you extend your elbows with your arms by your sides, and simultaneously draw your elbows behind the plane of your trunk, the long heads of your triceps contract more strongly than it does if you keep your elbows by your sides.
Working the triceps when the long head is neither stretched nor fully contracted — as when you lie on your back with your arms extended toward the ceiling — places the long head in its strongest position. This allows you to handle more weight, which adds another dimension for development; in addition to orientation of the upper arm, load is key to growth of the triceps.
“Some research has suggested that you get the best triceps workout with exercises that stretch the muscles beforehand,” says Contreras. That would include overhead movements like triceps extensions. “But I’ve found that for complete development, it’s just as important to fully lock out your elbows and squeeze the triceps hard,” he says.