Pec Deck: how to do it right
In short: The pec deck isolates the pecs in horizontal adduction, with a peak of tension in the shortened position, arms brought together in front of you.
How to do it, step by step
- 1Set the seat so the handles are at mid-chest height, back flat against the pad.
- 2Arms slightly bent and fixed, open until you feel a comfortable stretch, without forcing behind the shoulder.
- 3Bring the handles together thinking about squeezing with your pecs, not pushing with your hands.
- 4At the end of the range, when your arms are close together, squeeze the contraction hard for 1 second.
- 5Control the return slowly over 2 to 3 seconds, without letting go all at once.
- 6Keep your elbows at a constant height throughout the movement.
The mistake to avoid
Don't lift your shoulders off the pad to push heavier.
Other common mistakes
- Bringing the arms together without squeezing at the end of the range: pause for 1 second with arms together to use the peak tension.
- Letting the elbows drop or rise: keep them fixed at shoulder height to target the middle of the pecs.
- Letting go of the return abruptly: brake the opening over 2 to 3 seconds so you don't lose tension.
- Opening too far back: stop the range at the comfortable stretch to protect the shoulder.
Muscles worked
- Main:
- Chest
The pec major is the prime mover, especially its sternocostal fibers (middle of the chest) that bring the arms together. The front delt assists slightly. Unlike a press, the triceps are out of the picture because the elbows stay fixed, which concentrates all the work on the pecs.
What to replace it with
Same muscle, same part of the movement: these exercises do the same job.
- Shoulder-Height Crossover Cable Fly ›
- Low-to-High Cable Fly ›
- High-to-Low Cable Fly ›
- Standing Band Chest Fly (Anchored Behind) ›
- Band Chest Press (Anchored Behind) ›
Frequently asked questions
How do I do this exercise?
Set the seat so the handles are at mid-chest height, back flat against the pad. Arms slightly bent and fixed, open to a comfortable stretch, then bring the handles together thinking about squeezing with your pecs, not pushing with your hands. Squeeze hard for 1 second with arms together, then control the return.
How far should I go?
Open until you feel a comfortable stretch, no more, the shoulder is fragile in extreme opening. The real work is at the end of the range: bring your arms well toward each other and squeeze for 1 second. Tension is highest in the shortened position, so never rush the closing.
I don't feel anything, is that normal?
On the pec deck you should feel the middle of the pecs, especially when you squeeze with arms together. Forget heavy: take a load you can hold for 1 second in contraction without shaking, and think about squeezing with your pecs, not pushing with your hands. Place it as a finisher after a press to go after the pump.
How fast should I do the movement?
Bring your arms together under control and squeeze for 1 second in the closed position. Then brake the opening over 2 to 3 seconds without letting go all at once. That braking and that held peak do all the work, not speed.
How do I breathe?
Inhale as you spread your arms, exhale as you bring them together toward the contraction peak. Keep your back against the pad and your abs lightly braced to stabilize the torso and not cheat with the trunk.