Standing One-Arm Dumbbell Triceps Extension
You hold a single dumbbell overhead with one arm, lower it behind your head by bending only at the elbow, then press it back up. It isolates the triceps through a long range of motion using nothing but a dumbbell, making it an easy add-on for anyone finishing an upper-body session at home or in a gym without a cable station.
Why it works
All three heads of the triceps straighten the elbow, but the long head also crosses the shoulder, so it gets more involved when your arm is raised overhead rather than down at your side. Lowering the dumbbell behind your head stretches that long head further than a pushdown or a lying extension would, which is why overhead variations tend to target it more directly. Because only one arm works at a time, you can also concentrate on keeping the elbow still and track exactly how each side moves, which is harder to feel with a two-arm barbell version.
Set up
- Hold a dumbbell in one hand and press it overhead until your arm is straight.
- Tuck your elbow in near your ear, steadying it with your free hand or simply holding it pointed forward.
- Keep your core tight and avoid arching your lower back to compensate for the overhead load.
How to do it
- Bend only at the elbow, lowering the dumbbell behind your head in a controlled arc.
- Stop once your forearm is roughly parallel to the floor or you feel a full stretch in the triceps.
- Keep your upper arm pointed at the ceiling throughout, without letting the elbow drift outward.
- Press the dumbbell back up by straightening the elbow until your arm is fully extended again.
- Complete all reps on one arm before switching sides.
Form cues
- Elbow stays pointed forward, not flared out to the side.
- Upper arm doesn't move, only the forearm swings.
- Lower until you feel a full stretch, not just halfway.
- Brace your core so your lower back doesn't arch.
Breathing: Inhale as you lower the dumbbell behind your head, exhale as you press it back to full extension.
Common mistakes
Letting the elbow flare outward as the dumbbell lowers.
Fix: Use your free hand to lightly guide the elbow and keep it pointed forward through the whole rep.
Using momentum from the shoulder to help lower and raise the weight.
Fix: Slow the tempo down and keep the upper arm locked in place so only the elbow joint moves.
Picking a dumbbell too heavy to control one-armed, causing the torso to lean or twist.
Fix: Drop the weight until you can keep your torso upright and still for every rep.
How to program it
- As an isolation finisher, 3 sets of 10 to 12 reps per arm fits well at the end of a push day.
- Keep the load moderate since the single-arm overhead position limits how much weight you can control safely, regardless of your triceps strength.
- Two to three sessions a week is reasonable for most people, since it's light accessory work rather than a heavy compound lift.
- Works well paired with a horizontal pressing move like a bench press, since that trains the triceps from a different joint angle.
Safety notes
- Keep the elbow pointed forward throughout; a flared elbow puts unnecessary stress on the joint.
- Choose a weight light enough that your shoulder stays stable overhead for the full set.
Exercise profile
- Force
- Push
- Mechanics
- Isolation
- Category
- Strength
Frequently asked questions
How many reps should I do for the standing one-arm dumbbell triceps extension?
Three sets of 10 to 12 reps per arm with a moderate dumbbell works well as accessory work after a pressing exercise.
What can I use instead if I don't have a dumbbell heavy enough to feel it?
A cable rope overhead extension lets you dial in lighter, more precise resistance and keeps tension on the triceps through the whole range.
Why does my elbow hurt during this exercise?
Elbow flare is the usual cause. Keep the upper arm pointed straight up and the elbow tracking forward instead of drifting out to the side, and drop the weight if you can't control the path.