Tricep Extension
The dumbbell tricep extension is a lying exercise where you bend only at the elbows to lower the weights towards your head, then straighten your arms to press them back up. It isolates the triceps, the muscles on the back of your upper arm, with the front of your shoulders helping to hold your arms steady. It suits beginners and experienced lifters who want stronger, bigger arms, as long as you start light and keep your technique tidy.
Muscles worked
The Tricep Extension mainly works your triceps, with your anterior delts helping.
Setting up
- Pick a light pair of dumbbells to start with, such as 4-8 kg each, and sit on the end of a flat bench holding them on your thighs. Lie back one at a time, using your knees to help lift the weights into position.
- Lie with your head, upper back and bottom on the bench and your feet flat on the floor. You can do this on the floor instead, with your knees bent and your feet planted.
- Press the dumbbells up over your shoulders with your palms facing each other and your arms straight. Keep your elbows soft rather than snapping them back.
- If you only have one dumbbell, sit upright on a bench with back support or a stable seat. Hold the dumbbell vertically with both hands cupped under the top head of the weight, and press it overhead.
How to do the Tricep Extension
- Start with the dumbbells directly over your shoulders, arms straight and palms facing each other.
- Take a breath in and squeeze the dumbbell handles. Keep your upper arms still and pointing at the ceiling.
- Bend only at the elbows and slowly lower the dumbbells towards either side of your head, taking about two to three seconds.
- Stop when the weights are just short of touching the bench or floor and you feel a good stretch down the back of your arms.
- Without letting your elbows drift, straighten your arms and press the dumbbells back up in a smooth, strong motion.
- Squeeze your triceps at the top, then repeat for your reps. Lower the weights to your thighs carefully at the end of the set.
Form tips
- Think of your upper arms as fixed in place. Only your forearms should move, like a hinge at each elbow.
- Keep your elbows pointing at the ceiling and roughly shoulder-width apart, rather than letting them flare out wide.
- Control the lowering phase. The slow stretch under load is where this exercise works your triceps hardest.
- At the top, push the dumbbells up by straightening your arms and squeeze the back of your upper arms for a moment.
- Stop each set with a couple of reps left in the tank. Control matters more than load, as the weights are travelling close to your head.
Common mistakes
Elbows drifting forwards and back
Your upper arms should stay still. If they swing, the exercise turns into a messy press or pullover. Reduce the weight and keep your elbows pointing at the ceiling throughout.
Elbows flaring out wide
Keep your elbows roughly shoulder-width apart and pointing upwards. Imagine your arms are on rails. Lighter dumbbells make this much easier.
Dropping the weights too fast
Lower for a count of two to three seconds, and only go as low as you can control. Stop just short of the bench or floor rather than bouncing or crashing the weights down.
Going too heavy
If you need to swing your arms, arch your back or lift your bottom off the bench to finish a rep, the weight is too heavy. Drop down until every rep looks the same.
Sets and reps
| Build strength | 3-4 sets of 6-8 reps with a challenging but controlled weight, resting 2 minutes between sets. |
|---|---|
| Build muscle | 3 sets of 10-15 reps with a slow lowering phase, resting 60-90 seconds between sets. |
| Fat loss and general fitness | 2-3 sets of 12-15 reps with a lighter weight, resting 45-60 seconds, as part of a full-body workout you can repeat consistently. |
Pick a weight where the last rep or two of each set is hard but your form stays clean. When every set feels easy, it's time to go up.
Tricep Extension alternatives
Machine taken, or want some variety? These work the same main muscles.
Tricep Extension FAQs
Is the dumbbell tricep extension a compound exercise?
No. It is an isolation exercise because only the elbow joint moves, and the triceps do most of the work. Your front shoulders help hold your arms in position. If you want a compound triceps exercise, try press-ups or a close-grip press.
How heavy should I go on the lying dumbbell tricep extension?
Start lighter than you think you need, often 4-8 kg per hand for beginners. Pick a weight that lets you complete 10-12 controlled reps with your elbows still. Add weight in small steps only when every rep feels the same.
Can I do tricep extensions with just one dumbbell?
Yes. Sit upright, hold one end of the dumbbell with both hands and press it overhead. Keep your elbows pointing forwards, lower the weight behind your head, then straighten your arms again. Use less weight than you would lying down, and stop if you feel any pain in your elbows or shoulders.
Track your Tricep Extension progress
GymTracker builds your plan, pre-fills the weight from last time and tells you when to go up. Free.
Start free