Machine Triceps Extension: how to do it right
In short: Machine elbow extension that isolates the triceps with a tension peak in the shortened position, arm straight.
How to do it, step by step
- 1Brace your back, elbows fixed under the pads or against the pad, aligned with the machine's axis.
- 2Start with the elbow bent and push to fully straighten the forearm.
- 3Go to the end of the extension without a harsh elbow hyperextension.
- 4Squeeze the triceps for 1 second at the end of the range, arm straight.
- 5Control the return over 2 to 3 seconds back to the starting flexion.
- 6Chain reps with no jerk or torso momentum.
The mistake to avoid
Don't do half reps. Fully extend your arms every time.
Other common mistakes
- Not fully straightening the arm: you miss the zone where tension is highest, go to the end of the extension.
- Swinging the torso to help: lock the trunk and let only the elbow move.
- Dropping the load on the return: brake the eccentric over 2 to 3 seconds so you don't lose tension.
- Going too heavy and cutting the range short: lower the weight to finish with the arm straight and squeeze for 1 second.
Muscles worked
- Main:
- Triceps
The triceps brachii does all the work. The lateral head (outer) and medial head (inner) lead the elbow extension, the long head (the long portion of the triceps) helps but is less recruited because the shoulder stays fixed. No notable secondary muscles, it's a pure isolation.
What to replace it with
Same muscle, same part of the movement: these exercises do the same job.
- Rope Triceps Pushdown ›
- Straight-Bar Triceps Pushdown ›
- Bent-Over Dumbbell Triceps Kickback ›
- Cable Triceps Kickback ›
- Reverse-Grip Triceps Pushdown ›
Frequently asked questions
How do I do this exercise?
Brace your back, elbows fixed under the pads or against the pad, aligned with the machine's axis. Start with the elbow bent and push to fully straighten the forearm, squeeze the triceps for 1 second with the arm straight, then come back under control. Only the elbow moves, the torso stays locked.
How far should I go?
Go to the end of the extension, arm almost straight, without locking the elbow sharply. That is where the tension is greatest, so never rush the end of the range. Squeeze for 1 second with the arm straight then come back to the starting flexion. Look for the full range you can control, not the one you reach by squirming.
I don't feel anything, is that normal?
You should feel the triceps burning at the end of the range. Slow down the last 20 degrees and deliberately squeeze the triceps for 1 second with the arm straight as if you wanted to snap the bar. That conscious contraction in the shortened position gives far more stimulus than quick, shortened reps.
How fast should I do the movement?
Push firmly to straighten, hold the contraction for 1 second with the arm straight, then brake the return over 2 to 3 seconds. It's this braking and that second of squeezing that do the work, not quick half-range reps.
How should I breathe?
Breathe in in the bent position, breathe out during the extension and hold the air at the end of the range through the second of contraction. Brace your abs and press your back against the backrest to stabilize everything.