FormTwin › Exercises › Chest Fly

What muscles does the Chest Fly work?

The chest fly isolates the pecs through a wide arc, stretching and squeezing the chest in a way that pressing alone can't.

Primary muscles worked

Secondary muscles worked

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How to do the Chest Fly

  1. Lie on a bench (or set cables at chest height).
  2. Hold the weights above your chest, slight elbow bend.
  3. Open your arms in a wide arc until you feel a chest stretch.
  4. Bring them back together, squeezing the pecs.

Common mistakes

Variations

Cable crossoverPec deckIncline dumbbell fly

Frequently asked questions

What muscles does the chest fly work?

The chest fly isolates the pectoralis major (chest), with a little front-delt involvement. The wide arc trains the chest's stretch and contraction more than a press does.

Fly vs bench press for chest?

The bench press is the heavy strength and mass builder; the fly isolates the pecs and emphasises the stretch and squeeze. Use presses first, then flys as an accessory.

Are chest flys bad for shoulders?

Only if you go too heavy or drop too deep. Keep a soft elbow bend and stop the stretch where it's comfortable to keep the shoulders safe.

Related exercises

DeadliftBack SquatBench PressPull-UpPush-Up

This guide is general fitness information, not medical advice. Muscle involvement varies with form, grip and individual anatomy. Consult a professional before starting a new program.