Exercise library · Chest

Pec Deck.

Isolation exercise designed to target the pectorals for chest adduction and definition, with minor anterior deltoid involvement.

Also known as: Pec Deck Fly, Machine Fly, Pec Fly Machine, Butterfly Machine

BeginnerMachine
The numbers
Sets
3–4
Reps
10–15
Rest
45–75 s
The play-by-play

How to do it.

  1. Step 01

    Sit on the pec deck machine with your back flat against the pad.

  2. Step 02

    Adjust the seat height so your shoulders and elbows are aligned with the pivot point.

  3. Step 03

    Place your forearms against the pads, with a slight bend in your elbows.

  4. Step 04

    Bring the pads together in front of your chest, squeezing your pectorals.

  5. Step 05

    Hold the contraction briefly at the peak of the movement.

  6. Step 06

    Slowly return the pads to the starting position, allowing a full chest stretch.

What separates good from great

Pro cues.

  • Avoid shrugging your shoulders; keep them down and back.

  • Focus on squeezing your chest muscles, not just pushing with your arms.

  • Control the eccentric phase to maximize muscle stretch and engagement.

Common questions

Questions, answered.

What is the Pec Deck?
Isolation exercise designed to target the pectorals for chest adduction and definition, with minor anterior deltoid involvement.
What muscles does the Pec Deck work?
The Pec Deck primarily works your chest. It also recruits your front delts as secondary movers.
What equipment do I need for the Pec Deck?
You need a machine to perform the Pec Deck.
How many sets and reps should I do for the Pec Deck?
A typical prescription for the Pec Deck is 3–4 sets of 10–15 reps. Rest about 45–75 seconds between sets.
Is the Pec Deck good for beginners?
Yes. The Pec Deck is a beginner-friendly movement, so it is a good choice when you are starting out, as long as you keep the load light and focus on form.

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