How to Do a Machine Fly

The machine fly is technically a seated variation of the bench fly that uses a weighted machine with handles for resistance instead of dumbbells. The pectoralis major of the chest is the primary muscle targeted by this exercise. The benefit of using the machine is that it encourages proper posture during the movement.

The machine fly encourages more of a stretch to the chest muscles, which works to promote the building of more muscles mass than other similar exercises. This opening of the chest can help to alleviate upper body tension and assists with daily activities such as pushing open doors and carrying heavy loads.

How To:

  • Before taking a seat at the machine, choose your preferred weight and remove any locking devices that may be engaged. Some machines have a foot bar that must be pressed down in order to bring the handles forward.
  • Check to make sure that the height of the seat will allow you to keep your feet flat on the floor while holding the handles of the machine at chest height.
  • Take a seat on the bench and make sure both feet are planted firmly on the floor. Handles should be held using a closed fist with thumb closed over the fingers. It is perfectly normal for the stretching in the chest to feel somewhat intense. This is not a position that is adopted in everyday activities so can feel strange at first. You should, however, make sure that the position of the handles does not pull your arms back further than your body.
  • Engage the chest and core, making sure you are sitting upright and not slouching, but also not arching the back. Take a breath in and exhale as you bring the handles forward until your hands are in front of your chest.
  • Hold this position for one breath and then inhale as you slowly return the handles back to their starting position.


Two sets of 10 are a good starting point for beginners. Always make sure that you are not so fatigued that your form suffers. If you feel your posture changing, readjust if possible and consider decreasing the amount of weight you are using or the number of repetitions you are performing.


The Pec Deck machine is similar to the chest fly machine in that it targets the chest and sees the user sitting upright to perform the maneuver, the only difference being that you are pushing two padded arm rests instead of handles.

This changes the position of the arms, somewhat decreasing the intense stretch to the chest. It can be beneficial for those who may be dealing with a wrist or elbow injury.

Cautionary Notes

Make sure not to hold your breath your while performing the exercise. This is called bracing, and while it can be helpful when dealing with extremely heavy weights, muscles need oxygen to perform at their best.

It is important to keep your shoulders and neck relaxed during the exercise. Too much tension, especially in the neck, can cause muscle strain.

Try not to press your feet into the floor. You may feel as if you are performing the exercise more efficiently, but it is important to realize that the goal is to work the chest, not the legs. If you feel you cannot perform the movement without using your feet, it is best to decrease the amount of weight you are using.

Try not to arch your back. You always want to be sitting up straight with your back firmly against the back rest. Not doing so can result in injury to the lower back.

Other Pectoral Exercises

Bench press
Chest fly

More Machine Fly Related Resources

Exercise Database (Chest22) – Seated Pec Fly Machine – Jase Stuart – The Better Body Coach
Machine Fly – Exercise Database | Jefit – Best Android and iPhone Workout, Fitness, Exercise and Bodybuilding App | Best Workout Tracking Software
How to Use a Chest Fly Machine: Techniques, Benefits, and Variations
Machine Fly (Chest)
Butterfly | Exercise Videos & Guides |
Machine fly exercise instructions and video | Weight Training Guide

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