Machine Biceps Curl: how to do it right
In short: Biceps isolation on a guided machine, with a tension peak in the shortened position, elbow bent and forearm raised.
How to do it, step by step
- 1Rest the back of your arm on the pad, elbow aligned with the machine's rotation axis.
- 2Grab the handles, shoulders down and back flat against the backrest.
- 3Bend the elbows to raise the forearm toward the shoulder, without lifting the arms off the pad.
- 4At the top, shortened position, squeeze the biceps hard for 1 second.
- 5Control the return over 2 to 3 seconds to near-extension, without fully relaxing.
The mistake to avoid
Don't let the weight drop. Control the way down.
Other common mistakes
- Not holding the contraction at the top: keep a clear 1-second squeeze where the machine loads the most.
- Lifting the arms off the pad to cheat: keep the back of the arm glued to isolate the biceps.
- Letting the return go all at once: brake the lengthening phase over 2 to 3 seconds.
- Misaligned elbow with the axis: adjust the seat so your elbow pivots on the machine's axis.
Muscles worked
- Main:
- Biceps
The biceps brachii is the prime mover, especially its short head on this type of machine where the elbow stays in front of the body. The brachialis (under the biceps) contributes to elbow flexion. The brachioradialis assists discreetly depending on the grip. Supination is limited by the fixed handle, which concentrates the work on pure flexion.
What to replace it with
Same muscle, same part of the movement: these exercises do the same job.
Frequently asked questions
How do I do this exercise?
Rest the back of your arm on the pad, elbow aligned with the rotation axis, shoulders down and back flat against the backrest. Bend the elbows to raise the forearm toward the shoulder without lifting the arms off, squeeze hard for 1 second at the top, then brake the return over 2 to 3 seconds.
How far down should I go?
This machine loads the biceps in the shortened position: the hardest point is the top, forearm raised and elbow well bent. Go all the way up, squeeze for 1 second at the top, then return while braking to near-extension without fully relaxing. Go for the full range you control, not the one you reach by wriggling.
I don't feel anything, is that normal?
You should feel it in the biceps, especially at the top during the squeeze. Imagine you're crushing a ball in the crease of your elbow at the top, and hold a clear 1 second. Add a few partial reps at the end of a set, only in the top, to extend time under tension where this machine excels.
How fast do I do the movement?
Curl up firmly, squeeze for 1 second at the top, then brake the return over 2 to 3 seconds. It's that braking and the held contraction at the top that do the work, not speed. Never swing with momentum.
How do I breathe?
Inhale before bending, exhale as you curl up and during the squeeze at the top. Keep your trunk braced and your back flat against the backrest so you don't compensate with the shoulders or torso.