Pec-Deck Fly (Butterfly Press)
This can be a useful companion exercise to the machine bench press. It allows you to work your chest muscles through a greater range of motion while keeping your body well supported.
Pec-deck fly (butterfly press) has an effect similar to that of the flat bench dumbbell fly. The difference is that you use a machine, commonly found in gyms, called a “pec deck.”
How to Perform Pec-Deck Fly?
STARTING POSITION (SETUP): Sit in a pec-deck station with your back straight or firmly against the backrest, plant your feet on the ground, and place your elbows and forearms on the pads. Your elbows are flexed at about 90º at the mid-chest level. For best results, position your arms so that your elbows fall just below your shoulders (your upper arms should be no higher than parallel with the floor), and limit the stretch to just behind your chest.
MOVEMENT (ACTION): Squeeze your pecs to bring the pads together in front of your chest. Flex your chest hard at the moment in the exercise when your elbows are together and always lower the weight under strict control. Don’t bounce. Breathe in as you open your arms as far as your flexibility will allow (for safety’s sake, you should open your arms less if you are using a heavy weight), and breathe out as you close.
Pec-Deck Fly Additional Tips
- Sit with head, shoulders, and back firmly against seat back.
- Your shoulders are in line with machine’s axis of rotation and upper arms are parallel to floor.
- Pull arm pads slowly together, exerting more force with the forearms than with the hands.
- Allow arm pads to slowly return to starting position.
Muscles Engaged in Pec-Deck Flyes
- MAIN MUSCLES: pectoralis major, deltoids (anterior)
- SECONDARY MUSCLES: coracobrachialis, subscapularis, biceps (short part)
- ANTAGONISTS: latissimus dorsi, deltoid (posterior), trapezius, rhomboids, teres
Pec-Deck Fly Variation
- Try other version of the fly machine that has handles instead of elbow pads (see machine fly exercise).
Pec-Deck Fly Substitutes
- Flat bench cable fly
- Flat bench dumbbell fly
Except the flying movements, there are also many other pressing movements to target your middle chest area. Each exercise works the middle pecs and supporting muscles slightly differently. Remember, specificity requires that you choose exercises that reflect your needs and goals. Visit our middle chest exercise database to find those exercises.
Pec-deck fly (butterfly press) provides optimum isolation of the pectoral muscles without bringing in the triceps. It allows a good level of congestion with medium to high repetition. It is recommended for beginners because of its simplicity, and for advanced athletes because of the specific recruitment of the muscles (making it an excellent complement to the bench press).
Pec-deck fly won’t build the pectoral mass and size that you can build with free weights (using pressing movement). However, the pec-deck machine can be extremely helpful in creating definition and shape in your chest. For greater control during the exercise, you can wrap your fingers around the tops of the pads.