Pec Deck Machine Fly
The pec deck machine fly is a machine exercise targeting the chest. The guided range of motion isolates the pectoral muscles and maintains constant tension throughout, making it effective for chest development with reduced risk of shoulder strain.
How to do it
- Sit on the pec deck machine and adjust the seat so your arms are parallel to the floor.
- Place your forearms against the arm pads or grip the handles with elbows bent at 90 degrees.
- Press the arm pads together in front of your chest by contracting your pectoral muscles.
- Pause at the peak of the contraction and squeeze your chest.
- Slowly allow the arm pads to return to the starting position and repeat for the desired number of repetitions.
Form cues
- Keep your back flat against the pad throughout the movement.
- Maintain a soft bend in your elbows without changing the angle.
- Squeeze your chest muscles together as your hands meet in the middle.
- Return slowly to the starting position with control.
Breathing: Exhale as you press the pads together, and inhale slowly as you return to the starting position.
Common mistakes
- Using too much weight can force your shoulders to rotate forward and increase joint strain.
- Bouncing off the weight stack reduces muscle engagement and compromises form control.
- Lifting your head off the back pad shifts tension away from your chest muscles.
Muscles worked
Primary: chest. Secondary: shoulders.
Suggested sets & reps
Get fitter
3 sets x 10-12 reps, rest 60 s
Lose weight
3 sets x 12-15 reps, rest 45-60 s
Build muscle
3-4 sets x 8-12 reps, rest 90 s
Easier, harder & alternatives
Make it easier
Make it harder
Alternatives
Take care if…
- If you feel shoulder discomfort, reduce the weight or limit your range of motion.
General educational guidance, not medical advice. Stop on sharp pain and check with a qualified professional if unsure.
Get this in your plan
Create a free account for an AI-built plan that puts moves like this into your week.
Start free →Frequently asked questions
Should I touch the weights together at the center?
It depends on the machine, but generally bring them close or lightly touch while keeping constant tension on your chest rather than clanging the plates.
Where should I feel this exercise?
You should feel a contraction and stretch across your pectoral muscles in the middle of your chest, not in your front shoulders.
How often can I do the pec deck machine fly?
Two to three times per week with at least one rest day between chest sessions is plenty for most beginners.