Chest exercise: Machine Fly
This is a variation of the dumbbell chest fly using a machine with either a hand grip (described in this post) or elbow pads. Machine fly 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. This exercise provides optimum isolation (single-joint exercise) of the pectoral muscles without bringing in the triceps.
Some seated fly machines (sometimes referred to as pec-decks) include arm pads to place the insides of your elbows and forearm on while keeping your elbows bent at roughly a 90-degree angle throughout the motion.
The biggest advantage of the arms open exercise (machine fly using vertical handles) is that the tension remains more or less constant over the whole of the movement and is not lost in the closing phase.
Machine Fly – Proper Exercise Technique
STARTING POSITION (SETUP): Sit in the machine, press your upper back and hips against the pads, and place your feet flat on the floor. Adjust the seat so that your shoulders, elbows and hands are on the same horizontal plane after you grab the handles. In other words, adjust the seat so that the handles are at chest level. Grasp the handles with a closed neutral grip; in this position, your elbows will be slightly flexed and your upper arms and forearms should be parallel with the floor.
EXECUTION (ACTION): With your back squarely against the pad, forcefully bring the handles all the way together, making sure to keep your elbows up to make the movement more efficient and to reduce the risk of injury. When your hands touch, squeeze your pectorals hard for a count. Reversing the motion, allow the handles to go back to a point at which you feel a strong stretch in your pecs before beginning your next rep. When returning to the starting position don’t let the weight rest on the stack.
Additional Tips & Key Points
- Bring the handles together in a wide arc with your elbows slightly bent (in a hugging motion) – they touch in front of your chest.
- When your knuckles touch contract your chest muscles. Be careful not to pinch your fingers between the handles.
- Move the pads in a smooth wide arc – do not jerk them together as this reduces the work on the pectorals.
- Main muscles: pectoralis major, deltoids (anterior)
- Secondary muscles: coracobrachialis, subscapularis, biceps (short part)
- Antagonists: latissimus dorsi, deltoid (posterior), trapezius, rhomboids, teres
Machine Chest Fly Variations (Modifications)
- Some fly machines (sometimes referred to as pec-decks) include arm pads to place the insides of your elbows and forearm on while keeping your elbows bent at roughly a 90-degree angle throughout the motion.
- Adjust the seat up or down to target different areas of the chest. Sitting higher up (when the seat is high and the handles are held low) emphasizes the lower pectorals; sitting lower (when the seat is low and the handles are held high) emphasizes the upper pectorals.
Machine Fly Substitutes (Replacement Exercises)
- Flat bench cable fly (see flat bench dumbbell fly post)
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.
The machine fly is another exercise that isolates the pecs. It allows for greater range of motion than the bench press. During a free-weight fly (using dumbbells), the resistance is very uneven over the range of motion. The tension is very high in the stretched position, which increases the risk of overstretching the tendons of both the chest and the long head of the biceps. As you bring the weights up, the resistance decreases dramatically. It is almost null at the top of the movement. The machine fly avoids these limitations because good machines do the following: (a) provide a gentler stretch of the chest muscles in the bottom position, and (b) keep more tension in the contracting phase of the movement. Therefore, it is wiser and safer to use a machine rather than dumbbells when performing flying movements.