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What Muscles Do Chest Flys Work?

    Do you strive for the “chest separation”? Chest fly exercises can give you that look. But how? What muscles do they work?

    Chest flys primarily focus on your chest. But the move also targets your arms, shoulders, and back. Having a strong chest improves your posture, helps you with daily activities, and reduces back pain.  

    Read on as we explore the benefits of chest flys, how to do them, and their variations. We’ll also give you some safety tips and tricks that help you perform the move correctly.

    Areas Engaged With Chest flys 


    Chest flys strengthen your pectorals⁠—muscles that connect the chest’s front wall to the shoulder and upper arm bones. These muscles help you draw your shoulders backward and inward. 


    Chest flys work your deltoids⁠—the major muscle in the shoulders wrapping your shoulder joint. 

    These muscles extend from your shoulder blade and collarbone and attach to your upper arm bone. They help you stretch, flex and rotate your arm. You also use these muscles when you lift things. 

    When you perform chest flys, you work the front and middle parts of your deltoids. The move also involves the muscles in the back of your shoulders. 


    While chest flys mainly work your chest and shoulder, they also involve the muscles in your arm and back. They work your rhomboid—the muscles between your spine and shoulders. 

    Besides, when you’re doing chest flys, the muscles that connect your ribcage to the shoulder bear some of the dumbbell load. So there’s also some engagement in these muscles. 

    The movement also works your rotator cuff—a group of muscles and tendons around the shoulder joint and your biceps—the large muscles on the front of the upper arm that provide arm flexion.

    Other Benefits 

    Chest flys also help open up your chest muscles, reducing the tightness and increasing the range of motion in your upper body. 

    Reducing back pain is another benefit of chest flys. 

    If you’re doing chest flys as a chest opener exercise, use lighter dumbbells or do it with no weights. Doing so helps you get the full range of motion and prevents you from overextending your arms, which may lead to an injury. 

    Moreover, chest flys help improve your shoulder blade integrity and strength, which gives you a better posture. 

    How To Perform Chest flys

    Chest flys are a great upper body workout, which use weights to strengthen your chest and arm. All you need is a pair of dumbbells. 

    Lay back with your knees bent on the ground. Keep your hands straight up your chest while holding dumbbells. Make sure your palms are facing each other. With a slight bend in your elbows, open your hands slowly to the side. Then go back to the starting position and repeat the movement.  

    Exhale and squeeze your chest as you bring the weights up and inhale as you lower them.  

    Perform two or three sets of 10 to 15 reps. 

    If you’re a beginner, start with light dumbbells (three to five pounds). Then gradually increase the dumbbell weight to 8 to 10 pounds as you become more advanced.

    You can also perform this move on an incline bench. Using an incline bench will help engage your shoulder muscles more. Besides, it puts less stress on your rotator cuff, which usually hurts when working out in a flat area. 


    Chest Fly Variations

    If you’re looking for more muscle engagement, here are some ideas. Do 10 to 15 reps for each. 

    V-Sit With Chest Fly

    Sit with your knees bent and heels on the ground. Hold your dumbbells at chest level with a slight bend in your elbows. Keep your core tight and lean back a few inches. While keeping your torso still, open your arms to the side and bring them to the center.  

    Besides working your upper body, this move enhances your balance and coordination and develops strength.

    V-Sit With Chest Fly

    Standing Chest Fly

    Stand with your feet shoulder-width apart and a slight bend in your knees. Hold a dumbbell in each hand and bring your hands to the front. Extend your arms to the side while keeping your arm at chest level. Then bring your arms down to the starting position and repeat the movement.

    This move helps tone your upper back and deltoid muscle. Keep your core tight to engage your abdominals too. 

    Watch this video to learn how to perform it properly:

    Chest Fly With An Stability Ball

    Lay back on a stability ball with your feet flat on the ground and your knees at a 90-degrees angle. Make sure your head, neck, and shoulders are supported by the ball. Keep your arms at chest level with a slight bend in your elbows. Then push the dumbbells straight up and open your arm to the side. 

    This move targets your chest to a great degree and helps you improve your balance and core stability. 

    Chest Fly

    Chest Fly With A Resistance Band

    Performing chest flys with resistance bands has the same benefits as doing chest with dumbbells.

    The Power System resistance band, available on Amazon, helps you engage more muscles while executing chest flys. 

    Anchor the resistance band behind you at your chest height. Bring one leg forward with a slight bend in the knee while keeping the other leg straight. Grab the band and bring your arms forward so that your palms are facing each other. Extend your arms to the side, stay there for a few seconds and bring your hands together. Then repeat.

    Watch this video to learn to do it properly:

    Safety Tips And Tricks

    These tips help you perform chest flys correctly to maximize the workout effectiveness and prevent muscle injury.

    Don’t Lock Your Arms

    As mentioned, you have to keep a slight bend in your elbows while performing chest flys. 

    When you lock your arms while pushing up the dumbbells, you force your elbows and shoulder joints to work and support the weights instead of your chest muscles. If you use heavy dumbbells, you may hurt yourself in the long run.

    Make sure to keep that bend in your elbows during the entire exercise to engage your chest area fully. 

    Avoid Overstretching

    Extending your arms too far and lowering the dumbbells close to the floor can cause injury and reduce chest engagement.

    When you’re in the starting position, Keep your arms aligned with your torso and avoid dropping your elbows too far.  

    Choose A Proper Dumbbell

    When choosing dumbbells, pay attention to your form and level and pick the weight you’re comfortable with. 

    Never lift heavy dumbbells to impress. When you go beyond your resistance, you’ll fatigue your muscles; as a result, you tend to drop the dumbbells too low with each rep. 

    Don’t Come Down Too Fast

    Performing the reps too quickly can also cause muscle fatigue, which forces you to drop the dumbbells in the middle of the set. It may also lead to an injury.

    Try to execute the move slowly. Lift the dumbbells for a one-second count and lower them for a two-second count. 

    Be in the Right Position

    Many people drop their heads when performing chest flys. This mistake will decrease chest engagement.

    When you do chest flys lying on the ground, the bench, or a stability ball, keep your head and shoulders firmly on the surface. 

    Bottom Line

    Chest flys are a great exercise for building muscles in your chest, shoulder, and arms. They also open your chest and improve your posture. Beside the traditional dumbbell chest flys, there are some variations that you can incorporate into your workout routine.  

    Chest flys have many benefits, but if you’re not careful, they can lead to muscle injury. 

    Last update on 2024-05-08 / Affiliate links / Images from Amazon Product Advertising API


    James Wright

    James (36) has been working out since he was 15 years old. He has a home gym where he pumps iron, does bodyweight workouts and boxing. He likes sharing his experiences with others who want to build a better physique.

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