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Strength Training · Bodybuilding

Machine Pec Fly

The machine pec fly, also called the pec deck, trains your chest by bringing your arms together against resistance while your back rests against a support pad.

  • Beginner
  • Isolation
  • Low injury risk
  • Rest 1 min
Video by Davis Diley on YouTube

How to do it

  1. Adjust the seat so your elbows sit slightly below shoulder height when you contact the handles or pads.
  2. Set the starting position so your upper arms are roughly in line with your torso.
  3. Sit with your back against the support pad and your feet flat on the floor.
  4. Grasp the handles with slightly bent elbows, or place your forearms against the pads on a padded model.
  5. Bring the machine arms together in front of your chest.
  6. Open your arms slowly back to the starting position.
  7. After your final repetition, ease the weight stack down to rest.

Form cues

  • Keep your shoulders away from your ears.
  • Keep your ribs down.
  • Exhale as your arms close.

Common mistakes

  • Turning the fly into a pressKeep the same elbow bend throughout the repetition rather than straightening your arms as you close.
  • Throwing your torso forwardReduce the weight until you can move the machine arms without rocking your body.
  • Bouncing out of the stretchReverse direction smoothly without using a rebound to start the next repetition.

Safety

Excessive weight or a starting position too far behind your body can strain the front of your shoulders. Fatigue can make it harder to control the return into that stretched position.

  • Test the machine's range with a light load before your working sets.
  • Use the entry-assist pedal if your machine has one.
  • Stop the set if you feel shoulder pinching or lose control of the return.

If you have current shoulder pain or a history of shoulder instability, use a shorter, comfortable range and seek advice from a physiotherapist before adding load.

Muscles worked

Front

Primary muscles

  • Chest

Equipment

  • Pec Fly Machine

Sets and reps

Sets
2–3
Target
10–15 reps
Rest
1 min

Choose a weight that leaves you able to perform about two more controlled repetitions at the end of each set.

Variations

Harder