What muscles does the incline fly work?

Your chest does the work, and the front of your shoulder assists more than most people realize. When the shoulder studies were pooled, the inclined dumbbell fly ranked highest of all exercises for the front head of the deltoid.

What angle should the bench be for incline flies?

Shallow. Nobody has tested angles on a fly specifically, but on the press version, sitting above 45 degrees significantly raised front-shoulder activity and reduced what the chest contributed. Since this movement already leans on the front delt, a slight tilt is the sensible default.

Is the incline fly better than the flat fly for the upper chest?

Nobody has compared them for growth. What tilting the bench definitely does is remove the dead spot at the top, since your arms never finish directly above your shoulders, and bring the front of the shoulder in much further.

How low should you lower the dumbbells on an incline fly?

Less far than you would lying flat. On a slope the upper arms already sit behind the line of your body before the rep begins, so the chest reaches its stretch sooner. Stop where the chest is stretched and the shoulder is comfortable.

Why do I feel incline flies in my shoulders?

Partly because the bench may be too steep, and partly because that is the nature of the movement. It is the highest front-deltoid exercise in the pooled research. A shallower tilt reduces it, but you will not remove it.

Should you do incline flies and incline presses on the same day?

You can. They do different jobs: the press bends the elbow so the triceps helps and the load can be heavy, and the fly keeps the elbow fixed so the chest swings the arm alone at a much lighter weight. Press first, since it is the movement worth being fresh for.

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Dumbbell · beginner · chest

Dumbbell flys incline

Also called Incline chest fly, Incline dumbbell flye, Upper chest fly, Incline dumbbell fly, Incline fly.

The short answer

The incline fly opens your arms out and back together on a sloped bench, with your elbow angle held fixed. Your chest does the work and the front of your shoulder assists heavily. Heavily is the word: in the review that pooled across studies, the inclined dumbbell fly came out top of the individual exercises for the front head of the deltoid, though the single trained-lifter comparison that ranked ten exercises put the shoulder press first. Either way it leans hard on the front delt, which is worth knowing before you file this under upper chest work.

How to do it

Step oneLie on an incline bench set to 30-45 degrees holding a dumbbell in each hand above your chest.
Step twoWith a slight bend in your elbows, lower the dumbbells outward in a wide arc.
Step threeContinue lowering until you feel a deep stretch in your upper chest.
Step fourBring the dumbbells back up in the same arcing motion to the starting position.

What usually goes wrong

Each starts with what you would notice.

You feel this almost entirely in the front of your shoulders.

WhyThe bench is set too steep. This movement already asks a lot of the front head of the shoulder at any angle, and sitting up higher hands it more.

FixDrop the bench toward the shallow end of its range so the tilt is slight. The press version of this movement has been measured across five angles and the chest gave up ground to the shoulder above 45 degrees, which is a useful marker even though it was not measured on a fly.

Your elbows open and close as the dumbbells travel.

WhyYour arm is bending on the way down and straightening on the way up, which makes this an incline press with a wide arm path rather than a fly.

FixLock a small bend at the elbow and refuse to change it. Check it at the bottom, where the temptation is strongest.

The bottom position pulls at the front of the shoulder rather than stretching your chest.

WhyOn a slope your upper arms already sit further behind your body than they do lying flat, before the rep has started. Lowering until your arms will not go any further adds range that your shoulder joint supplies rather than your chest.

FixStop where your chest is stretched and your shoulder still feels settled, which will be higher than you expect on an incline. If something hurts and keeps hurting, that is a question for a physiotherapist.

You slide up the bench a little further with each rep.

WhyA fly gives you nothing to push against. On a press you can drive your feet into the floor and wedge yourself; here your arms are out to the sides and there is no bracing point, so gravity walks you up the slope.

FixPlant your feet and settle your weight down into the seat before you begin, then reset between sets rather than shuffling mid-rep.

Incline fly or flat fly

Tilting the bench does two things, and one of them is not usually mentioned.

The first is that it changes where in the range the load lives. Lying flat, a fly is hardest at the bottom and almost weightless once the dumbbells arrive over your shoulders, because that is where the weight sits directly above the joint. Tilted back, your arms never finish straight up, so the dumbbells never reach that dead spot and there is still something to hold at the top.

The second is the cost. The front of your shoulder is far more involved on the incline. Across the pooled shoulder research, the inclined dumbbell fly was the highest exercise of all for that head. So an incline fly is not a flat fly moved upward, it is a flat fly with the shoulder taking a considerably bigger share.

If your shoulders are what you feel on this movement, that is not a form problem you have failed to solve. It is the exercise.

Incline fly or incline press

The difference is the elbow, and it decides everything else.

A press bends and straightens the elbow, so the triceps can contribute and you can load it much heavier. A fly holds the elbow at one angle throughout, so your arms are just a fixed shape that your chest swings, and the weight has to be small.

That makes the press the movement to put weight on and the fly the one that reaches a stretched position the press stops short of. Doing both is coherent; replacing the press with the fly is not.

The upper-chest movement with the biggest front-delt reading

This is sold as the exercise that fills out an upper chest. Two things get in the way of that.

The first is that whether incline work reliably grows a differently shaped chest is not settled, and the evidence that exists was gathered on presses, not flies. Nobody has trained a group on incline flies and measured the result.

The second is more awkward. In the review that pooled across studies, this movement topped the individual exercises for front-deltoid activity. It is a strange candidate for the purest upper-chest exercise when it also sits at the front-shoulder end of that ranking.

None of that makes it a bad movement. It loads the chest at a stretch with your shoulder tilted back, and it keeps some load at the top of the rep where a flat fly has none. Do it for those reasons and expect your front delts to be part of the deal.

What it is for

Incline dumbbell flys are an isolation exercise targeting the upper chest. The inclined angle directs the stretch and contraction toward the upper pectoral fibers, complementing pressing exercises to build a fuller upper chest.

Questions people ask

What muscles does the incline fly work?: Your chest does the work, and the front of your shoulder assists more than most people realize. When the shoulder studies were pooled, the inclined dumbbell fly ranked highest of all exercises for the front head of the deltoid.
What angle should the bench be for incline flies?: Shallow. Nobody has tested angles on a fly specifically, but on the press version, sitting above 45 degrees significantly raised front-shoulder activity and reduced what the chest contributed. Since this movement already leans on the front delt, a slight tilt is the sensible default.
Is the incline fly better than the flat fly for the upper chest?: Nobody has compared them for growth. What tilting the bench definitely does is remove the dead spot at the top, since your arms never finish directly above your shoulders, and bring the front of the shoulder in much further.
How low should you lower the dumbbells on an incline fly?: Less far than you would lying flat. On a slope the upper arms already sit behind the line of your body before the rep begins, so the chest reaches its stretch sooner. Stop where the chest is stretched and the shoulder is comfortable.
Why do I feel incline flies in my shoulders?: Partly because the bench may be too steep, and partly because that is the nature of the movement. It is the highest front-deltoid exercise in the pooled research. A shallower tilt reduces it, but you will not remove it.
Should you do incline flies and incline presses on the same day?: You can. They do different jobs: the press bends the elbow so the triceps helps and the load can be heavy, and the fly keeps the elbow fixed so the chest swings the arm alone at a much lighter weight. Press first, since it is the movement worth being fresh for.