To (dumbbell) fly or not to fly? About the effectiveness and safety of dumbbell chest flyes

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Dumbbell flyes are the final exercise of many chest workouts. “It’s like hugging a tree,” Arnold Schwarzenegger said. The ‘Austrian oak’ was right. But likely a very thick tree, which you cannot get your arms around.


Flyes are perhaps the best-known chest isolation exercise. Unlike the bench press, your elbow joint and triceps are sidelined, leaving your pectoral muscles to do all the work. Therein lies the power of flyes. Plus, the ROM (range of motion) is greater, allowing your chest muscles to stretch and contract to the maximum.

Flyes especially provide a better stretch of the chest at the bottom of movement than the barbell press, research shows. Which makes sense, since the barbell can’t lower beyond the chest. In addition, the chest fly appeals to a different function of the chest than the press, namely adduction, i.e. moving your chest and shoulders towards the center of your body. This puts more emphasis on the outer part of the pectoralis major muscle (the pectoralis major).

In short, it is logical that in addition to one or a few pressure exercises, you also include at least one fly movement in your training program (possibly supplemented with persuasion, or pullovers ).

Traditionally, the chest fly is performed with dumbbells, usually on a bench, which looks like this:

However, this variant is criticized by many coaches. Are they right? Let’s take a closer look at the exercise.


A much-discussed aspect of chest flyes in general is the positioning of the elbows . According to  unofficial research by coach Kassem Hanson, this is the best positioning:

  • at the bottom of the movement (the last part of the eccentric phase) bend the elbows slightly (about 15 to 20 degrees);
  • during the peak contraction (the last part of the concentric phase) straighten/extend the elbows.

In this way you create the greatest range of motion (ROM) and the safest position for both shoulders and humerus.

For the dumbbell fly it looks like this:


Another tricky point, specifically with the dumbbell chest fly: how low can you go? According to coach Mike Israetel, you should go deep enough to feel a good stretch in your pecs, but not so deep that you feel uncomfortable pressure on your shoulders. If the tension in your chest disappears and your shoulders start to feel uncomfortable, you’re going too deep.

No one is the same anatomically, but in general the elbows should be slightly below the back in the lowest position.


The dumbbell fly is often criticized for the lack of resistance in one part of the exercise. How about that?

In the bench press, for example, you apply force directly against the resistance. Simply put: the weight wants to go straight down (just let go) and you push it in the opposite direction, so straight up. The resistance curve and strength curve follow the same line. To lift the weight, you must exert as much force as you encounter resistance. In fact, this applies to all movements in a straight line, but not to circular movements such as dumbbell flyes.

With dumbbell flyes, the dumbbell moves not only from the bottom up, but also from the outside in. This while it is only pulled straight down by gravity. As a result, the resistance and consequently the tension on your muscles slowly decreases, so that the dumbbell fly is hardly effective in the upper, say, 30 degrees of the movement.

dumbbell fly effectivenessIn the green area, your chest muscles offer the most resistance. (Source: T Nation)

Is that a reason to pass the dumbbell fly? Not necessarily: constant tension is not a condition for muscle growth. So it’s okay if the tension on the muscle disappears for a while between two repetitions. That makes a set easier, but you can also use more weight. Now it is neither the intention that you ‘rest’ for a long time between two repetitions, especially not with an isolation exercise. That is why we advise you not to bring the dumbbells all the way together, but to skip the last part (the red area in the picture above). That means you end the rep with your arms pointing more or less straight up:

This is an important difference from cable flyes and machine (pec deck) flyes, which do provide constant resistance and tension on your muscles throughout the movement. With these variants, you do bring your hands fully together at the end of the movement.


The question of whether it is better to do flyes on a flat or inclined bench is easy to answer. Flat flyes target your entire pectoral muscle, while inlcine target the upper part a little more. Just like for the incline (dumbbell) press, we recommend a small angle (between 15 and 20°) for incline flyes.


According to Mike Israetel, flyes are best done in the range of 10 to 20 reps (the absolute intensity), as is common in isolation exercises. So use relatively light weights, namely for your safety, to achieve the best mind-muscle connection and to avoid bending your elbows too much to use more biceps. Train your sets to near muscle failure, with 1-2 RIR and possibly the last set to complete muscle failure (the relative intensity).

For optimal muscle growth in your chest, depending on your training status, you should do 10 to 20 sets per week (the training volume), divided over presses and flyes, possibly supplemented with pullovers.

Don’t make it ‘Monday, chest day’: train your chest two or three times a week (the training frequency), with a maximum of 5-10 sets per training (the session volume).


Are cable or machine flyes better than dumbbell flyes? Some coaches, including Menno Henselmans, think so: he recommends seated cable flyes (with the back against the backrest), a variant that he called Bayesian Flyes. This is on the one hand because of the constant tension that the use of cables creates, on the other hand because, according to him, this position is less stressful for the shoulder joint.

According to another respected coach, the aforementioned Mike Israetel, cable flyes aren’t so much better than dumbbell flyes (perhaps quite the opposite), but thanks to the resistance in the front part of the movement, they may target the middle of the chest a bit better:

Thus they are not “better” than dumbbell flyes and for overall pec hypertrophy, probably worse, but they are better for something specific that you might be trying to accomplish during your current training phase.

In addition, we already saw that Israetel sees little harm in the dumbbell fly with regard to the shoulders, as long as you don’t go too deep.


Yet the latter is the reason for us to recommend cable or machine flyes in the first place: not everyone is equally able to sense when the arm is moved too far backwards, a risk that is less with cable flyes and machine flyes. Moreover, the resistance in those fly variants is evenly distributed, while the center of gravity with the dumbbell fly is precisely in that potentially vulnerable position for the shoulders. And we know from experience how relatively fragile the shoulder joint is and how long it can take to recover from a shoulder injury.

Looking purely at effectiveness, however, it doesn’t really matter which variant you choose, as long as you apply progressive overload. The dumbbell fly is certainly no less effective than other flyes, possibly on the contrary, precisely because of the greater resistance in the stretch position. The lack of resistance in the top position can be avoided by not bringing the hands all the way together.

If you focus specifically on the middle of your chest, resistance in that top position is important and so you should do a cable or machine fly, where you do bring your hands together.

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