Reverse Flyes
Reverse flyes hinge you forward at the hips and raise a pair of light dumbbells out to the sides, targeting the rear deltoids, the part of the shoulder muscle facing backward that most pressing and pushing exercises barely touch. It's a small, deliberate movement rather than a heavy one, built around control rather than load. Anyone who presses, benches, or sits at a desk most of the day benefits from it, since it directly counters the forward-rounded shoulder posture those activities tend to reinforce.
Why it works
The rear deltoid pulls the arm backward and outward, a direction most gym pushing work never trains, which is why it's one of the most commonly underdeveloped muscles relative to the front and side of the shoulder. Hinging forward at the hips orients your torso so gravity pulls straight down on the dumbbells rather than toward your chest, putting the rear delts in the best position to resist that pull as you raise your arms out to the sides. Trained consistently, that direct work helps balance out the front-dominant pattern built by pressing, benching, and everyday posture.
Set up
- Pick a pair of dumbbells noticeably lighter than what you'd use for a lateral raise; this muscle is small.
- Hinge forward from the hips until your torso is close to parallel with the floor, keeping a slight bend in your knees.
- Let the dumbbells hang directly below your shoulders with your palms facing each other.
- Keep your neck in a neutral line with your spine, looking slightly ahead rather than straight down.
How to do it
- Raise both dumbbells out to the sides in a wide arc, leading with your elbows rather than your hands.
- Keep a slight, fixed bend in your elbows throughout the movement instead of locking them straight.
- Continue until your upper arms are roughly in line with your torso, or until your shoulder blades stop squeezing together.
- Pause briefly at the top, feeling the squeeze across your rear shoulders and upper back.
- Lower the dumbbells back down slowly along the same arc, resisting gravity rather than dropping them.
Form cues
- Hinge first, then raise.
- Lead with the elbows, not the hands.
- Small, controlled arc, not a big swing.
- Neutral neck, eyes slightly ahead.
Breathing: Exhale as you raise the dumbbells out to the sides, inhale as you lower them back down.
Common mistakes
Standing too upright instead of hinging forward at the hips.
Fix: Commit to the forward hinge until your torso is close to parallel with the floor; standing tall turns this into a shrug rather than a rear delt raise.
Using momentum to jerk the dumbbells up.
Fix: Slow the pace down and stop using any weight you need to swing to move. A controlled two-second lift is more effective here than a fast, heavy one.
Rounding the lower back to compensate for tight hamstrings in the hinge.
Fix: Bend your knees a bit more if hamstring tightness is pulling your back out of a flat position; a slightly bent knee is better than a rounded spine.
Shrugging the shoulders up toward the ears during the raise.
Fix: Keep your shoulders pulled down and away from your ears; the trapezius shouldn't be doing the work meant for the rear delts.
How to program it
- Three sets of 12 to 20 light reps is the typical range, since this muscle responds well to higher volume at a low load.
- Twice a week is usually enough for most people, given how much indirect rear delt work already happens during rowing and pulling exercises.
- Add it near the end of a shoulder or pull session rather than at the start, once the bigger lifts for the day are already done.
- If your upper back rounds forward by the end of the day, this is one of the more direct fixes to build into a regular routine.
Safety notes
- Skip the heavy end of your dumbbell rack for this movement; the rear delt is small and a heavy load almost always turns into momentum, not muscle work.
- Stop the set if you feel the movement shifting into your lower back rather than staying in your shoulders.
Exercise profile
- Force
- Pull
- Mechanics
- Isolation
- Category
- Strength
Frequently asked questions
What muscles do reverse flyes work?
Mainly the rear deltoids, the part of the shoulder facing backward, along with some support from the upper back muscles that pull your shoulder blades together.
How much weight should I use for reverse flyes?
Start lighter than feels reasonable. Most people can only handle 5 to 10 pounds per hand with strict form, since the rear delts are a small muscle group.
Can I do reverse flyes without dumbbells?
Yes, a cable rear delt fly or a resistance band pulled apart at chest height trains the same muscle if dumbbells aren't available.
Why don't I feel reverse flyes in my shoulders?
Usually the torso isn't hinged forward enough, or the weight is heavy enough that momentum and the traps are taking over. Lighten the load, hinge further forward, and slow the tempo down.