Exercise guide
Dumbbell Lying Alternate Extension
- Intermediate
- Isolation
- Rep-based
- Chest
- Upper arms
This exercise isolates the triceps long head by utilizing an incline to increase the stretch, while the alternating pattern challenges unilateral stability and mind-muscle connection.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Set an incline bench to a 30-45 degree angle.
- Sit back on the bench with a dumbbell in each hand, feet planted firmly on the floor for stability.
- Press both dumbbells directly above your chest with a neutral grip (palms facing each other).
- Slightly tilt your upper arms back toward your head so they are at a 75-80 degree angle relative to your torso.
How to do it
- Inhale and slowly lower one dumbbell toward your shoulder by bending only at the elbow, keeping the upper arm completely stationary.
- Lower the weight until your forearm passes parallel or you feel a deep stretch in the triceps.
- Exhale and contract the triceps to extend the arm back to the starting position.
- Repeat the movement with the opposite arm while keeping the non-working arm locked out in the starting position.
Form checklist
- Keep your elbows tucked in and pointing forward; do not let them flare out to the sides.
- Ensure the upper arm (humerus) remains fixed throughout the entire set to isolate the triceps.
- Maintain a neutral wrist position to avoid unnecessary strain on the joint.
- Keep your lower back pressed against the bench and avoid arching as the weights lower.
Pro tips
- Keep the non-working arm under slight tension at the top to act as a stabilizer and increase time under tension.
- Focus on a slow, 3-second eccentric (lowering) phase to maximize micro-tears in the muscle fibers for better growth.
Make it harder
- Pause for one second at the bottom of each repetition to eliminate elastic momentum.
- Perform the movement with a slight internal rotation at the bottom to further emphasize the lateral head.
Frequently asked
- What muscles does the dumbbell lying alternate extension work?
- The dumbbell lying alternate extension primarily targets the triceps, and also works the abs and obliques as secondary muscles.
- What equipment do you need for the dumbbell lying alternate extension?
- The dumbbell lying alternate extension uses dumbbell.
- Is the dumbbell lying alternate extension good for beginners?
- The dumbbell lying alternate extension is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.