Upper Arms Exercise · Dumbbell
Dumbbell One Arm Triceps Extension (on Bench)
Also known as: Dumbbell One Arm Tricep Extension (On Bench), Db One Arm Triceps Extension (On Bench), Dumbell One Arm Triceps Extension (On Bench)
- Category
- Upper Arms
- Equipment
- Dumbbell
- Target
- Triceps
Biomechanical cues verified by the PlanWorkouts Science Review Board under CSCS editorial oversight; see our editorial standards.
The Dumbbell One Arm Triceps Extension (on Bench) is a targeted isolation upper arms movement designed to train the Triceps.
Single-joint elbow extension isolating the triceps brachii (lateral, medial, and long heads). Keep upper arm fixed to prevent shoulder momentum. Executing this with strict form maximizes muscle fiber recruitment while protecting joint structures.
Quick Exercise Facts
Target Muscle Activation
Bracing on a bench for a one-arm overhead extension stabilizes the torso so the triceps can be trained in isolation without the balance demands of a standing version. That support lets the working arm focus purely on extending against resistance through a full overhead range. It's a good option for really honing in on triceps strength differences between arms.
How to Do the Dumbbell One Arm Triceps Extension (on Bench)
- Sit on a bench, keeping your back straight and both feet flat on the floor.
- Grip a dumbbell in one hand and brace your other hand on the bench for stability.
- Lift the dumbbell overhead, tucking your upper arm close to your head with your elbow pointed forward.
- Bend your elbow to lower the dumbbell behind your head, keeping the upper arm fixed.
- Straighten your elbow fully to bring the dumbbell back up to the top.
- Continue for your target number of reps, then switch arms.
Recommended Sets & Reps by Training Goal
65–75% 1RM · 60s rest
50–60% 1RM · 30–45s rest
Controlled 3s eccentric · 60s rest
Biomechanical & Joint Load Cues
Single-joint elbow extension isolating the triceps brachii (lateral, medial, and long heads). Keep upper arm fixed to prevent shoulder momentum.
Common Mechanical Mistakes & Form Errors to Avoid
- Flaring Elbows Outward: Allowing elbows to wing outward during pushdowns or extensions shifts tension to the chest and shoulders while stressing elbow ligaments.
- Moving the Upper Arms: Swinging the humerus back and forth turns the movement into a lat pullover rather than isolated elbow extension.
- Incomplete Lockout Extension: Stopping short of full arm extension prevents full recruitment of the triceps medial and lateral heads.
Proper Breathing Patterns & Core Engagement
Inhale as elbow flexes to full stretch; exhale as forearm extends straight.
Add the Dumbbell One Arm Triceps Extension (on Bench) to Your Custom Workout Routine
Build a personalized, science-backed workout plan matching your training goals, equipment access, and schedule.
Injury Modification & Joint Safety
Individuals with triceps tendon irritation at the elbow should avoid excessive deep elbow flexion (>90°) on skull crushers and prefer cable pressdowns. If joint irritation persists, immediately stop and substitute this movement with another exercise from the Upper Arms exercises category.
Muscles Worked
The Dumbbell One Arm Triceps Extension (on Bench) primarily targets the Triceps, with Shoulders as the primary synergist muscle group.
More Upper Arms Exercises
Assisted Standing Triceps Extension (with Towel)
Assisted Triceps Dip (kneeling)
Band Alternating Biceps Curl
Band Close-Grip Push-Up
Band Concentration Curl
Band One Arm Overhead Biceps Curl
More Triceps Exercises
Band Side Triceps Extension
Barbell Close-Grip Bench Press
Barbell Decline Close Grip To Skull Press
Barbell Incline Close Grip Bench Press
Barbell Incline Reverse-Grip Press
Barbell Jm Bench Press
Equipment Alternatives
Don't have dumbbell? These target the same triceps with different equipment.
Bench Dip (knees Bent)
Band Side Triceps Extension
Barbell Close-Grip Bench Press
Cable Alternate Triceps Extension
FAQ
- What muscles does the Dumbbell One Arm Triceps Extension (on Bench) work?
- The Dumbbell One Arm Triceps Extension (on Bench) primarily targets the triceps as the primary agonist. The shoulders acts as the primary supporting muscle group during force transmission. Maintaining strict biomechanical alignment ensures maximal tension remains focused on the intended muscle fibers rather than shifting to surrounding stabilizer joints.
- What equipment do I need for the Dumbbell One Arm Triceps Extension (on Bench)?
- The Dumbbell One Arm Triceps Extension (on Bench) is performed using a dumbbell. Ensure all equipment is securely positioned with collars or safety pins locked before loading working sets. If you train in a home gym or minimal setup, explore our equipment-free and resistance band alternatives below.
- What is the most common form mistake on the Dumbbell One Arm Triceps Extension (on Bench)?
- The most frequent error is flaring elbows outward: Allowing elbows to wing outward during pushdowns or extensions shifts tension to the chest and shoulders while stressing elbow ligaments.. Controlling the 2 to 3-second eccentric lowering phase ensures maximal hypertrophic stimulus while shielding connective tissue.
- How many sets and reps should I perform on the Dumbbell One Arm Triceps Extension (on Bench)?
- For muscle growth and density, execute 3 to 4 working sets of 10 to 15 controlled repetitions with 60 seconds rest, emphasizing a deep stretch and deliberate peak contraction on every rep.
- What's a good alternative to the Dumbbell One Arm Triceps Extension (on Bench)?
- If you don't have access to a dumbbell, the Bench Dip (knees Bent) targets the same triceps using body weight instead. This alternative replicates the same joint angle and movement plane while allowing you to train effectively with different available gear. You can also substitute it seamlessly in our free Workout Plan Builder.