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All About the Chest Fly: Muscles Worked, How To, Benefits, Common Mistakes, and More

 Written by 

Julien Raby

 Last updated on 

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Whether you’re looking to bulk up, build upper body strength, or just tone your pecs, this article is for you. The chest fly is a simple chest exercise with plenty of options to keep your muscles working. We’ll explore all the ins and outs of the chest fly and answer the most-asked questions. Let’s see how we can improve your pecs with the chest fly!

What Muscles Does a Chest Fly Work?

Just as it sounds, the chest fly works the upper chest muscles as well as the lats, deltoids, upper abs, and lower abs. It’s an isolated movement meant to specifically target the chest. But as a bonus, it also works the following muscles.

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Although a chest fly focuses on the pectoralis major and the anterior deltoids, the lats, or latissimus dorsi, come into play as a stabilizing muscle. As you move through the motion of the chest fly, the lats hold everything steady and get stronger as they support your chest muscles.

Upper Abs

The upper abs include the rectus abdominis and external obliques. They also act as a stabilizing muscle as you squeeze through each chest fly. You’ll naturally strengthen your upper abs as you engage them in each repetition.

Lower Abs

The lower abs, or transverse abdominis, get a nice workout too. They are engaged and tightened throughout each chest fly movement. Using proper technique works your abs from top to bottom giving you an all-over toned look.

Upper Chest

Made up of the pectoralis major and the pectoralis minor, the chest fly is meant to isolate this group of muscles, and you’ll notice a change in no time using this exercise. The biceps also act as a support muscle during the movement but as you squeeze through each rep you’ll feel it in those primary chest muscles.

What Equipment Do You Need to Do a Chest Fly

The only equipment you need for a chest fly is a set of dumbbells. To add variation and range of motion you can also use a weight bench with your dumbbells or a chest fly weight machine.

We’ve outlined below how to simplify and modify to make the chest fly more advanced. Let’s take a closer look!

How to Do a Chest Fly Correctly

Whether you’re using a machine or dumbbells, we’ll make sure you know how to perform this exercise safely and effectively. Let’s dive into the ins and outs of chest flys and explore the difference between dumbbells versus machines!

Begin by lying flat on a weight bench with your feet shoulder-width apart and both dumbbells tightly gripped in each hand. Lift the weights straight above your chest and inhale as you slowly lower them until they are parallel to your chest. As you bring the weights down, squeeze your shoulder blades together and engage your core. 

Return to the starting position at the top of the movement, exhaling as you do so, and repeat. We recommend 10-15 reps and a total of 3 sets.

Common Mistakes People Make with Chest Flys

As with any exercise, there are bound to be mistakes you’ll want to be aware of so you can avoid injury. We’ve included all the details you’ll need to watch out for below.

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Relying on Momentum

You might think faster is better, but that speed can cause your form to spiral out of control. Going too fast and relying on momentum to lift the weight can seriously increase your risk of injury. We recommend slowing it down and concentrating on getting the technique right. Remember slow and steady wins the race when it comes to chest strength.

Holding Your Breath with Each Extension

If you find yourself holding your breath while performing the chest fly, you might be concentrating too hard or lifting too heavy. Pay attention to your breathing. Inhale as you lower and exhale as you lift the weight back to starting position.

Matching your breath to body movement will improve your overall health and help your muscle recovery as it sends oxygen to the muscles just when they need it most. It also aids in the mind-body connection.

Engaging Your Legs

Another common mistake we see is engaging the legs. If you find yourself using your legs to sustain your momentum by pushing them into the floor, try using a lighter weight.

Always check your technique and focus on squeezing the chest muscles as you breathe through the movement. If your abs are tight and engaged, it will also take the strain off your legs. 

Arching Your Back

Arching your back could also be a sign that your weight is too heavy and you should lower it. Engage your core throughout the entire chest fly movement to help prevent your back from arching. As you focus on engaging your core and squeezing the upper chest, your back should stay flat against the floor or bench.

A Few Safety Tips and Precautions

It’s always wise to check with a doctor before beginning any new training regimen or trying out new moves. Especially if you’re just starting out or are prone to any type of shoulder or back injury.

Always be aware of your form and know the proper technique for each move you’re doing. If you’re unsure of the proper technique or feel like you need a little extra guidance to get you going, we recommend consulting a personal trainer. A personal trainer can also help you establish a training plan that works best for you and your lifestyle and needs.

Benefits of the Dumbbell Chest Flyes

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There are so many benefits to incorporating the chest fly into your weekly lifting routine. It increases your overall well-being and offers a balanced set of moves to help build the muscles in your upper chest. Let’s go over a few more benefits in a little more detail.

Better Range of Motion

You’ll notice an increase in the range of motion you have and that chest flys also serve as a chest opener. Chest openers help reduce things like back pain, and they prevent tight upper body muscles as they’re stretched in this movement.

Just make sure you don’t overextend the arms when using a weight bench. The floor can be a good measuring tool to help keep your arms in the correct range of motion.

Maximizes Chest Muscle Gains

Because of its isolated nature, a chest fly naturally produces the best results for chest muscle gains. You’ll notice an increase in muscle mass within just a few short weeks. You’ll be lifting heavier weights in no time by adding the chest fly into your weekly routine.

Improved Posture

Your posture will improve in a big way as you naturally put your body in the right position to build muscles correctly. Whether you’re using the bench or the floor, both of those variations help to keep your backside in proper alignment, creating the posture you want. You’ll notice yourself walking and sitting a little taller as time goes by.

Stronger Core

Engaging those abdominal muscles throughout the entire movement of the chest fly will tone your midsection and support the muscle growth happening in the upper chest. As you squeeze through each chest fly, pay attention to how that core works through each breath to movement, giving you a stronger, leaner core in no time.

Helps Prepare for Other Exercise

Having a stronger chest will help prepare your body for other exercises such as push-ups and bench presses. It will enable you to perform other exercises with greater ease and better technique.

The chest fly is a known complement to the chest press because it works the smaller supportive muscles. Those smaller muscles being worked in the chest fly can help improve your bench press exponentially

Dumbbell Chest Fly Variations

Once you’ve mastered the basic dumbbell chest fly, you’ll want to check out the variations we’ve outlined below. Switching up your basic moves with a little variety will keep you motivated and work those upper chest muscles in a wider range of motion.

Hollow Body Chest Fly

The hollow body chest fly is a great way to work your abs in a more advanced manner while getting that upper body work done. You get to work two major muscle groups in one movement.

You apply your basic dumbbell chest fly move with your abs contracted and your legs elevated to a 90-degree angle the entire time. Breathe through each set and let those abs and chest muscles rest for about 30-60 seconds in between each set. Maintain a tight grip on those weights and don’t go too heavy when you’re first starting out.

Incline Bench Fly

The incline bench fly is very similar to your basic chest fly except that you’re working on an incline angle, which works more of the upper part of your chest and shoulders. Get into starting position with both dumbbells gripped tightly. Lean back, squeeze your shoulder blades together, lift the weights straight above you, and extend the weights out to the midline. Repeat.

Standing Chest Fly

For this variation, set the dumbbells aside and grab a resistance band. The resistance created by the dumbbells makes it impossible to do a chest fly while standing as gravity naturally places all of the weight onto the shoulders.

Once you’ve firmly gripped the resistance band, check that you’re in a split stance. Slightly bend your knees. Bring the resistance bands straight in front of you and extend your arms outward until they’re parallel to your chest. Bring the bands back to starting position and repeat.

Banded Dumbbell Fly

For this move, loop the resistance bands around each dumbbell with the midsection of the band under your back as you get into starting position on the weight bench. Lift the dumbbells straight above your chest, just as you would in a basic chest fly. Extend the arms out to your sides so they’re parallel with your upper body.

Adding the band to the dumbbells will maintain constant tension on your muscles throughout the entire movement. This is a more advanced move that will chisel your upper body in a shorter amount of time. If you’re ready to kick it up a notch, this is a great move to use!

Cable Chest Fly

The cable chest fly is similar to the standing chest fly except you’re using the machine instead of resistance bands. This variation gives you the option of adding more weights, which can help you lift heavier loads versus the resistance band.

Get into a split stance just as you would with the standing chest fly. Check that the pulleys are at about elbow height. Grab each handle and center yourself between the weights. Align your spine upright with your core engaged. Bring the handles forward until they’re straight out in front of you and slowly lower them back to parallel position. Repeat.

Stability Ball Fly

Incorporating the stability ball into your chest flys is a great way to work your abs! It also helps alleviate any back pressure you may feel using the bench or the floor as your abs are forced to remain engaged.

With your upper back on the ball and feet firmly planted at shoulder width apart, grip both weights and engage your core. You’re ready to lift the weights straight over your chest, inhaling as you go. Once you get to the top, slowly lower back down, exhaling as you do so. Repeat.

FAQs About Chest Flys

We figured you’d have some questions about chest flys, and we’ve come up with the most commonly asked questions we could find. Hopefully, the answers below cover anything we’ve missed. However, if you have a burning question that we’ve missed please reach out and let us know!

Is a Pec Fly and Chest Fly the Same?

A chest fly and a pec fly are pretty close to the same thing. Pec fly is short for pectoralis fly, which is the primary muscle we’re targeting when performing the chest fly or pec fly. Depending on which way you rotate your hands and arms, you’ll place a greater or lesser emphasis on the pecs.
For example, if you externally rotate your hands and arms during the fly, the movement will place more emphasis on the pectoralis major. If you internally rotate your hands and arms throughout the movement, the shoulders will take on additional weight, which takes some emphasis off the pecs.

How Much Weight Should I Use for Chest Fly

If you’re brand new to lifting weights, always start small with weights ranging from 3-10 pounds. If that weight is too light, try something between 10-15 pounds. Once you’ve mastered that amount, you can go up to 25-30 lbs, which would still be considered novice level.
An intermediate lifter will be lifting closer to 50 lb dumbbells and a more advanced lifter will be using somewhere between 80-115 pound weights.

Are Chest Flys Good for Everyone?

As long as you get the all-clear from your doctor, and you aren’t nursing any shoulder injuries, anyone should be able to do the chest fly. The ability to modify this exercise with lighter or heavier weights makes it ideal for anyone looking to work their upper body.


Julien Raby is the owner of BoxLife. He owns a bachelor in literature and a certificate in marketing from Concordia. He's Crossfit Level 1 certified and has been involved in Crossfit since 2010. In 2023 he finally made it to Crossfit Open Quarterfinals for the first time. LinkedIn Instagram Facebook

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