Alternating Dumbbell Lying Triceps Extension
In SetGrip: Dumbbell Lying Triceps Extension (Alternating)
- Secondary muscles
- Delts
- Body part
- Upper Arms
- Position
- Lying
- Laterality
- Alternating sides
- Category
- Strength
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Working one arm at a time while the other stays extended turns this into half extension, half isometric hold. The straight arm gets a long static contraction while the moving side works through its rep, and the pace forces stricter control than lowering both dumbbells together, which is why it suits lighter loads and newer lifters.
How to do the Alternating Dumbbell Lying Triceps Extension
- Lie flat on a bench with a dumbbell in each hand, palms facing each other.
- Extend your arms straight up over your chest, keeping a slight bend in your elbows.
- Lower one dumbbell down towards your head, bending at the elbow, while keeping the other arm extended.
- Pause for a moment at the bottom, then raise the dumbbell back up to the starting position.
- Repeat with the other arm, alternating sides for the desired number of repetitions.
Tip: Keep a slight bend at the top on lying extensions to protect the elbow, but lock out fully on cable pushdowns.
Muscles worked
Primary
Triceps · Arms
The triceps straighten the elbow, and overhead variations stretch the long head at the bottom, so you should feel the whole back of the upper arm working with a hard squeeze at lockout.
Secondary
- Delts — The front delt holds the upper arm in position on overhead extensions and should feel tension but not be lifting.
Common mistakes
- Elbows flaring out — on overhead and lying extensions the elbows should stay pointed forward or up, not out to the sides, since flaring turns it into a press.
- Upper arm moving — the upper arm should be pinned in place and only the forearm should move; if the elbow drifts, drop the weight.
- Not finishing the rep — take every rep to a full triceps squeeze; on pushdowns that means a complete lockout for a count.
- Cutting the stretch — on overhead extensions let the weight travel down behind the head until you feel the long head stretch before pressing up.
Sets, reps and where it fits
| Goal | Sets × reps | Rest |
|---|---|---|
| Muscle growth | 3–4 × 10–15 | 60–90 s |
| Endurance / finisher | 2–3 × 15–20 | 45 s |
| Strength | Not ideal — pick a compound lift for the same muscle | — |
Triceps extensions go after the presses in a push session or at the end of an arm day. Superset them with biceps curls on the same cable stack or with the same dumbbells.
Variations and alternatives
Similar exercises
Without dumbbell
Frequently asked questions
What muscles does the Alternating Dumbbell Lying Triceps Extension work?
The Alternating Dumbbell Lying Triceps Extension primarily works the triceps. It also involves the delts, which assist the movement and stabilise the joints.
Is the Alternating Dumbbell Lying Triceps Extension good for beginners?
Yes. The Alternating Dumbbell Lying Triceps Extension is rated beginner: it uses a dumbbell and the movement is simple to learn. Start light, focus on the full range of motion and add load once every rep looks the same.
What can I do instead of the Alternating Dumbbell Lying Triceps Extension?
If you cannot do the Alternating Dumbbell Lying Triceps Extension, try the Banded Single Arm Side Triceps Extension, the Machine Triceps Extension or the Single Dumbbell Dumbbell Skull Crusher. Each of them trains the triceps through a similar movement, so you can swap them in without changing the rest of the workout.
How many sets and reps should I do?
It depends on your goal. For the Alternating Dumbbell Lying Triceps Extension, a sensible starting point is muscle growth: 3–4 × 10–15 with 60–90 s rest; endurance / finisher: 2–3 × 15–20 with 45 s rest. Do it after your compound lifts. It is a finishing movement, not the main event.
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Exercise data and animations are licensed ExerciseDB content used in SetGrip. This page is for general information and is not medical or coaching advice.