Rear Delt Fly: A Complete Guide

Quick Intro

Rear Delt Fly, also called the Bent Over Lateral Raise, is an isolation strength exercise performed by hinging forward at the hips and raising a pair of dumbbells out to the sides, leading with the elbows, then lowering them back under control. It’s a dedicated builder for the back of the shoulder and upper back, using dumbbells as the main equipment.

Equipment Needed

Rear Delt Fly needs a pair of Dumbbells, the only equipment this exercise requires.

Why Rear Delt Fly Matters

Raising the dumbbells out to the sides from a bent-over position isolates the back of the shoulder (deltoid, posterior) directly, with the upper back (trapezius), the muscles between the shoulder blades (rhomboids) and a muscle near the armpit (teres major) all assisting to pull the shoulder blades together as the arms lift. Muscular endurance is the main demand, since a light-to-moderate load has to be raised and lowered from a bent-over position through a full set, with strength second.

When to Do It

Rear Delt Fly works well as an accessory movement after the day’s heavier pulling or pressing work, once the back of the shoulder is ready for direct, isolated attention that most pulling exercises only partially provide. Spacing hard sets two to three times a week, with recovery in between, gives the joint room to adapt to the bent-over loading.

Anyone with a current lower back condition should approach this lift with some caution, since holding a forward hinge for a full set adds sustained demand to the lower back on top of the shoulder work. Bracing the core and keeping the hinge shallow enough to hold comfortably is a reasonable way to reduce that risk.

Getting Ready

Practicing the forward-leaning hinge without any dumbbells, just to find a torso angle that’s comfortable to hold, is worth doing before weight is added. Rolling the shoulders through a few slow circles afterward loosens the joint before the first loaded rep.

Once heavier dumbbells are in use, one lighter warm-up set lets the shoulder and lower back adjust to holding the bent-over position under load before the first hard set.

Step-by-Step Instructions

1. The setup. Hinge forward at the hips until the torso is near parallel to the floor, holding a dumbbell in each hand with a slight bend in the elbows.

2. The raise. Raise both dumbbells out to the sides, leading with the elbows, squeezing the shoulder blades together as the arms reach shoulder height.

3. The hold. Pause briefly at the top with a full contraction between the shoulder blades.

4. The lower. Lower the dumbbells back down under control to complete the rep, maintaining the forward hinge throughout.

How Many, How Often

Rear Delt Fly is dosed by reps, sets and the weight of the dumbbells, with the working weight chosen relative to how well the forward hinge holds through a full set.

Hinging forward until the torso is near parallel to the floor and leading the raise with the elbows, squeezing the shoulder blades together at the top, matters more here than the weight used, since a torso that stands too upright quietly turns this into a lateral raise.

Modifications and Variations

Rear Delt Fly has two alternatives, one done standing upright and one done lying on a bench.

As an alternative that shifts the raise to the side of the body from a standing position, Lateral Raise performs a similar raising path without the forward hinge, isolating the side of the shoulder.

As an alternative that adds support for the torso, Prone Rear Delt Fly lies face-down on an incline bench instead of hinging forward while standing, removing the lower back demand this standing version carries.

Progression path: Rear Delt Fly as the standard bent-over version, with Lateral Raise as a related alternative for the side of the shoulder and Prone Rear Delt Fly as a supported alternative for the lower back.

Common Mistakes to Avoid

Standing too upright instead of holding a full forward hinge. Without a hinge close to parallel, the movement drifts toward a standard lateral raise and stops isolating the rear shoulder the way this exercise intends. Holding the torso near parallel to the floor throughout the set keeps the emphasis on the back of the shoulder.

Letting the hands lead the raise rather than the elbows. Hands that rise first pull tension away from the rear deltoid and shift it toward the arms. Leading with the elbows and squeezing the shoulder blades together keeps the muscles between them working.

Rounding the lower back to hold the hinge. A rounded spine under a sustained forward lean adds unnecessary strain to the lower back over the course of a set. Bracing the core and keeping the spine neutral throughout the hinge protects the back while the shoulders do the work.

After Your Set

This lift raises the heart rate only slightly from holding the hinge, so a minute of easy standing movement settles it before stretching begins. Reaching both arms across the chest and pulling gently with the opposite hand stretches the rear shoulder that just worked through the raise. A gentle standing forward fold afterward releases the lower back and hamstrings that held the hinge throughout the set.

Going Deeper

Rear Delt Fly usually sits as an accessory movement after heavier pulling or pressing work, giving the back of the shoulder direct, isolated attention that most compound exercises only partially provide. Pairing it later in a session with a front or lateral delt exercise gives the shoulder balanced development across all three heads of the muscle.

Progress here tends to stall on hinge posture, not raw shoulder strength: as the dumbbells get heavier, it becomes tempting to stand up slightly to make the raise easier, which quietly shifts the work off the rear deltoid and onto the trapezius. Dropping the weight and rebuilding a stable forward hinge tends to unstick this faster than simply adding heavier dumbbells to an upright, compensating pattern.

Someone new to this lift generally learns a stable hinge and a controlled raise within the first few sessions, and works up to a weight that challenges the rear shoulder for a full set somewhere in the four to six week range.

How to Know You’re Improving

1. A forward hinge that stays close to parallel through the entire set
2. A raise that leads with the elbows, not the hands
3. A working weight that has grown while the hinge position stays stable
4. A clear squeeze between the shoulder blades at the top of every rep

A stable hinge held through the whole set, not the weight on the dumbbells, is what marks progress here.

Muscles Worked

• Posterior Deltoid (the back of the shoulder cap, lifting the arms out and back from a bent-over position)
• Trapezius (the upper back and neck muscle, holding the shoulder blades from shrugging up as the arms rise)
• Rhomboids (the muscles between the shoulder blades, drawing the blades together at the top of the raise)
• Teres Major (a small muscle under the shoulder blade, contributing as the upper arms travel backward)

FAQ

Why does this exercise need a forward hinge? Hinging forward changes the angle of resistance so it lands on the back of the shoulder, which is exactly why standing too upright turns the movement into Lateral Raise (see Common Mistakes above).

Is Rear Delt Fly the same as Lateral Raise? No, though they share a similar raising path. Lateral Raise is performed standing upright and isolates the side of the shoulder, while this version’s forward hinge shifts the emphasis to the back of the shoulder and upper back instead.

Why does my lower back get tired before my shoulders on this exercise? This usually means the hinge is being held for longer than the lower back can comfortably brace, which is common for anyone new to sustained forward-leaning positions (see When to Do It above). Bracing the core more deliberately or shortening the set tends to help.

What’s the benefit of Prone Rear Delt Fly over this version? Prone Rear Delt Fly lies face-down on an incline bench, removing the lower back demand of holding a forward hinge, which makes it a reasonable alternative for anyone whose lower back fatigues before their shoulders do.

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Related to Lateral Raise and Prone Rear Delt Fly.