The Dangers of Dumbbell Flyes & (How to Avoid Them)

Every bodybuilding enthusiast needs to be aware of the dumbbell fly. In this simple exercise, the elbow stays at a fixed angle while the hand and arm move through some part of their range of motion.

The shoulder joint is one of the most sensitive in the human body and an injury there can take ages to heal, and the biggest danger of the dumbbell fly is that people overextend their shoulder joints, fail to keep their elbow at a fixed angle, or add too much weight.

All of these mistakes can not only minimize the gains you get but more importantly, they can lead to serious injury.

Far too often, people who are desperate to build muscle leap at the chance to do dumbbell flyes and jump into the exercise with such gusto that they move too fast, jerk their arms through the motion, and again use too much weight.

Due to the unique functions of the shoulder joint and the pectoralis major, and also due to the absence of any power from the rest of the arm, you simply cannot handle as much weight during a dumbbell fly as you can with a bench press or other dumbbell exercises. 

Dumbbell flyes give the shoulders, chest, and triceps a great workout.

There are a handful of exercises you can use to target the shoulders and the pectoral muscles, but flyes have the unique advantage of targeting your chest muscles’ ability to move toward the center of the body, a motion called abduction.

It’s not difficult to alter your dumbbell fly so that you can protect your shoulder joint, avoid injury, and get great gains in your chest.

The number one thing you need to do is come to terms with the fact that your one-rep max is not coming into play during a fly. Be prepared to lift about 60% of that amount of weight or potentially much less depending on the state of your chest muscles when you start. 

The dumbbell fly can improve range of motion and build upper body strength in three critical muscle groups. 

Safety is a huge component of any chest workout because they so frequently involve the shoulder joint. Fortunately, the safest way to do dumbbell flyes is to do them with the right form, which will also greatly increase the amount of muscle gains they give.

Read on for some tips to get the perfect dumbbell fly form so you can get ripped pectoral muscles and prevent shoulder joint injuries. 

What Is a Dumbbell Fly?

The dumbbell fly is an exercise that’s meant to work out the horizontal range of motion of the arms. To a certain extent, they get a bad rap because if they aren't performed correctly, it could lead to injury or poor results. It’s also fair to say that there are variants of the chest fly that are safer and more effective than the traditional dumbbell fly. 

One of the most dangerous parts about the dumbbell fly in this start position is that there is no support whatsoever for your shoulder joint, so don’t try it unless you’re used to chest workouts or you already know you have the proper form. 

The move itself is relatively simple.

The starting position for a dumbbell fly is lying down on a flat bench with your hands each holding a dumbbell and extended straight up above you.

Next, to lower the weight you'll pull your arms apart toward either side of your body until your elbows are parallel with your back. In no scenario should you ever allow your arms to overextend lower than the level of your back as this can lead to injuries at your shoulder joint.

Return to the starting position and remember to keep a slight bend in your elbow to make sure it doesn’t strain too much. 

The Dangers of Dumbbell Flyes

From the description laid out so far, you might be thinking there’s nothing to the dumbbell fly. It certainly doesn’t seem like there’s a great risk of injury because you likely won’t even feel a stretch until you’re almost at the lowest point of the exercise.

In fact, that’s the most dangerous part.

You’re feeling your rib cage stretch and the coracobrachialis, which is an integral part of the shoulder joint, takes on all of the weight if you hyperextend lower than your back or stretch your arms out further. 

The danger is that this might just feel like the normal stress your muscles go through in a typical chest workout, but it’s a highly vulnerable position for the coracobrachialis and the surrounding muscle groups.

Even worse, your pectoral muscle is useless in any abduction past a certain degree, which means you’re putting your shoulder joint at serious risk of injury with no benefit whatsoever. 

Here are a few more ways standard dumbbell flyes on a flat bench can be extremely dangerous and fail to deliver on the bodybuilding goals you’re after:

Dumbbell Flyes Can Cause Long-Lasting Damage

Not to be alarmist, but if you’re trying to pump heavy weight in a dumbbell fly and you’re approaching the point of muscle exhaustion, don’t count on your ability to let the weight go. Your arm may dip under the weight and the hyperextension plus the sudden jerking movement can do all sorts of damage to your scapular muscles. 

Working with the rotator cuff, the scapular muscles allow for three-dimensional movement of the shoulder joint.

If you knock your scapular muscles out of whack doing a reckless dumbbell fly, it could cause long-term problems like scapular dyskinesis. Some people find that they can’t even lift their arm or arms after a comparable injury and it might last for years if it ever totally heals at all. 

In short, doing a dumbbell fly in a situation where you can hyperextend the shoulder joint won’t just mess up your bodybuilding ambitions for now. It could lead to years of at best suboptimal and at worse fully inhibited lifting ability.

Dumbbell Flyes Are Limited

They are meant to activate the pectoralis major muscles and they do a great job of that, but for all the risk they put on the shoulder joint, they only work the pecs and the anterior deltoids to a certain extent.

Other isolation exercises like bicep or wrist curls have the advantage of being so simple that you can throw them into a bodybuilding routine at any stage.

Dumbbell flyes, on the other hand, require much more dedication. 

That’s not to say you won’t see muscle gains if you add chest flies to your bodybuilding routine, but the tradeoff is not as high with these dumbbell flyes unless you do the correct variation to maximize muscle activation and reduce the risk of injury to your shoulder joint.

Use Less Weight When Doing Dumbbell Flyes

Far from being a recommendation, your body physically cannot handle as much weight at the end range of motion. That’s because at the critical end range at the bottom of the exercise where they are out to either side, your pectoralis major cannot engage to hold the weight. Through the rest of the range of motion, it can, but at either end of a standard dumbbell fly on a flat bench, your pecs are going to be completely deactivated. 

Adding more weight doesn’t help.

That’s actually the most common reason for injury in any chest fly. Think about it: if your pectoralis major is powerless at the bottom of a dumbbell fly, then there’s a much higher chance of muscle failure resulting overextension.

How to Avoid Dumbbell Fly Injuries

For all this risk, chest flies are still a great targeting exercise for your pecs, two of the most visible muscles in the upper body. Luckily, there are plenty of dumbbell flye variations and some easy tips that will help you do dumbbell flyes that give great gains without all the danger.

1. Dumbbell Fly Without a Flat Bench

All that risk of hyperextension in a dumbbell fly is because there is nothing to support your arms in case the weight becomes overwhelming or you experience muscle failure. To negate this risk factor, skip the flat bench and do your dumbbell flyes on the floor. It’s a simple way to limit the risk of overextension.

If you’re dead set on using some kind of bench, try using an incline bench.

An incline dumbbell fly is only different because of the comparatively more elevated position, but that’s enough to give you some room in case you need to drop the dumbbells. It doesn’t offer the guarantee against overextension, but because your arms will fall down rather than back if your muscles fail in the inclined position, incline dumbbells flyes are much safer. 

2. Use A Spotter

It’s the same recommendation we all got our first time at the gym, but so many people continue to ignore it: Get a spotter.

Any chest exercise on a flat bench or an incline bench is much safer with a spotter and if you can find one with some knowledge about the exercise you’re doing it can also help you notice when you stop using the correct form. 

For some reason, bodybuilding has become an isolated endeavor for many people.

Whatever the reason is, it seems to cause most people to give up on finding a spotter and go it alone. But having a spotter on hand who can take the weight away or support your arms can save a long-term injury to your rotator cuff.  

3. Pay Attention to Your Shoulders

Whether it’s on an incline bench or the floor, pay attention to your shoulder blades when you get into the starting position. They should be activated and aimed slightly inward so that your pecs are raised and your shoulders are set back. You should also squeeze your shoulder blades and make sure not to let off throughout the exercise. 

Continued squeezing with angled shoulder blades can help prevent shoulder injuries.

It can also be a good indication to stop because you might find yourself unable to keep concentrating on your shoulder blades as your muscles get more exhausted. Don’t keep pushing it, especially if you’re still on a flat bench for some reason. It will lead to muscle failure and if you’ve stopped pushing your shoulder blades back and clenching them, your shoulder joint is at a greater risk of injury. 

4. Listen to Your Body

One way dumbbell flyes done in the incorrect form keep surviving to cause serious and long-lasting injury to people is because there are some people who just have a greater range of motion in their shoulder joints. It could have to do with their body type or with the amount that they work out.

In any case, don’t keep doing this exercise if your body is trying to tell you to stop. Feel for straining muscles and make sure stretching is coming from the triceps and pectoralis major and not cartilage in the ribs or the coracobrachialis in the shoulder joint. 

If your shoulder seems to be tight, consider moving to shoulder-opening exercises regularly over a sustained period to improve the range of motion there. It will build your shoulders and reduce the likelihood of injury later on. 

Cable Flyes: The Chest Exercise You Could Be Doing Instead

Long story short, if you want to cut out the dumbbell flyes on a flat bench but get the same muscle activation, consider doing cable flyes instead. You can do cable flyes standing up without the risk of having the weight fall on your shoulder joint and causing a serious tear in the rotator cuff or worse.

Beyond the safety aspect, cable flyes are a great workout for your shoulder, deltoids, triceps, and pecs. 

Think about the dumbbell fly and how it is essentially useless at the top and bottom because it doesn’t engage the pecs then. When you do the cable fly, your pecs aren’t activated at the start position but they are for the rest of the move. That’s great because it means once you get back to the starting position, your shoulder joint is safe from injury. 

There’s also constant resistance on your pecs throughout a cable fly, unlike the dumbbell fly.

The weight allows you to keep a consistent pace without jerking and the cable fly allows you to bring your hands across the body’s centerline, further engaging the pectoralis major. All of this adds up to a chest exercise that will increase the range of motion in your shoulder joint and promote hypertrophy in your pecs. 

Conclusion:

Safety should be the main concern when you perform any kind of chest fly. For improved safety, you can skip the flat bench fly altogether and move to the floor or at least an incline bench. Always bring a spotter who can help you in case of muscle failure.

If at all possible, do cable flyes for a much better workout and significantly lower risk of injury to muscle, ligaments, and tendons around the shoulder joint.