Lateral Raises vs Reverse Fly: Differences & Muscles Worked

Key Takeaways

• Lateral raises primarily target the middle deltoids (side shoulders) while reverse flys focus on the rear deltoids and upper back muscles.
• For complete shoulder development, both exercises should be included in your training program rather than choosing one over the other.
• Proper form is crucial for both movements—lateral raises require controlled movement with slight elbow bend, while reverse flys need a hinged position and retracted shoulder blades.
• Reverse flys excel at improving posture and countering the effects of prolonged sitting, making them especially valuable for office workers.
• SOLE's SW180 Adjustable Dumbbells provide the precise weight progression needed for both exercises, while the SW116 Weight Bench enables optimal positioning for incline reverse fly variations.

Shoulder Sculpting: How Lateral Raises and Reverse Flys Differ

Choosing between lateral raises and reverse flys shouldn't be an either/or decision. These complementary exercises target different parts of your shoulder complex, serving unique purposes in a well-rounded fitness routine. 

The most fundamental difference between lateral raises and reverse flys lies in which part of the shoulder they target. Lateral raises primarily work the middle deltoid (the side portion of your shoulder), creating that coveted shoulder width and "cap" appearance many fitness enthusiasts seek. They're performed by lifting weights outward to your sides, creating abduction at the shoulder joint.

Reverse flys, on the other hand, target the posterior deltoid (rear shoulder) along with the rhomboids and middle trapezius muscles. This exercise involves pulling weights outward while bent forward, creating horizontal abduction and engaging the entire upper back region. Because the rear deltoids are often underdeveloped compared to the anterior (front) and lateral portions, reverse flys serve as an excellent corrective exercise for balanced shoulder development.

Both movements are isolation exercises that target specific muscle groups within the shoulder region, but they work entirely different portions of the deltoid muscle. The way you perform each movement, the equipment you use, and even when you incorporate them into your workout can significantly impact your results.

Lateral Raises Explained: Technique and Form

The lateral raise might appear simple, but proper execution requires attention to detail, including elbow position, movement control, and shoulder positioning throughout the range of motion.

Proper Execution of Lateral Raises

Keep a slight 10–15 degree bend in your elbows throughout the entire movement to protect the joint while maintaining proper mechanical advantage. 

Raise the weights with your arms slightly in front of your body, about 30 degrees forward from directly lateral, for optimal middle deltoid activation. This positioning reduces impingement risk while maximizing target muscle engagement.

Control the descent rather than letting gravity pull the weights down; the eccentric (lowering) phase builds significant strength and muscle when performed with control. Maintain a neutral wrist position throughout the exercise, avoiding any backward bending that can cause strain. Focus on initiating the movement from the shoulders, not the traps or arms, to ensure proper muscle activation.

A common variation is the seated lateral raise, which helps eliminate momentum and ensures strict form. You can also perform this exercise using cables, resistance bands, or machines, each offering slightly different resistance profiles throughout the movement arc. 

For instance, cables provide more consistent tension throughout the range of motion compared to dumbbells, which follow a gravity-dependent resistance curve.

Common Form Mistakes to Avoid

Despite the apparent simplicity of lateral raises, several common mistakes can reduce effectiveness and increase injury risk. Swinging the weights using momentum is perhaps the most prevalent error, which shifts tension away from the deltoids and can strain the shoulder joint. This usually happens when using weights that are too heavy for strict form.

Another frequent mistake is shrugging the shoulders during the movement, which transfers the work to your upper trapezius rather than targeting the deltoids. Keep your shoulders down and away from your ears throughout the exercise. 

Additionally, raising the weights too high (beyond parallel) can cause impingement issues and doesn't provide additional deltoid activation.

Watch for wrist positioning as well; allowing your wrists to bend backward during the movement can lead to strain and diminish your ability to control the weight. Maintain neutral wrists with thumbs slightly higher than pinkies (the "thumbs up" position) for optimal mechanics and safety.

Reverse Flys Breakdown: Movement Patterns and Setup

Reverse flys require more setup than lateral raises due to the bent-over position, with proper torso angle and spine alignment being crucial for effectiveness and safety.

Step-by-Step Reverse Fly Technique

Begin by selecting an appropriate weight; typically lighter than what you'd use for lateral raises since rear deltoids are often weaker than middle deltoids. 

Stand with feet shoulder-width apart and hinge forward at the hips until your torso is at approximately a 45-degree angle to the floor. Keep your spine neutral, core engaged, and knees slightly bent for stability.

Hold the dumbbells with a neutral grip (palms facing each other) directly beneath your shoulders. 

Maintain a slight bend in your elbows throughout the movement, then raise the weights out to the sides in a wide arc until they reach shoulder height. Imagine pinching a pencil between your shoulder blades at the top of the movement, then slowly lower the weights back to the starting position with control.

Form Errors That Diminish Results

Poor form during reverse flys not only reduces effectiveness but can also lead to injury. One major mistake is rounding the back instead of maintaining a flat spine throughout the movement. This places unnecessary stress on the lumbar spine and reduces the work done by the target muscles.

Using excessive weight often leads to reduced range of motion and compensatory movements that shift the work away from the rear deltoids. You should be able to feel the rear shoulder and upper back muscles working throughout the full range of motion. If you can't maintain proper form, reduce the weight.

Another common error is allowing the head to drop or jut forward during the exercise. Keep your neck in a neutral position aligned with your spine, looking at the floor a few feet in front of you rather than straight down. This helps maintain proper spinal alignment and prevents neck strain.

Avoid lifting with your biceps by initiating the movement from your shoulder blades rather than bending your elbows. Don't lift the weights too high; aim for shoulder height maximum to maintain optimal tension on the target muscles. 

Keep your movements controlled and avoid jerking or swinging, which indicates weight that's too heavy. Maintain retraction of the shoulder blades throughout the movement, and focus on a full range of motion rather than heavy weight.

Muscle Activation Comparison

Primary Muscles Targeted by Lateral Raises

Lateral raises primarily target the middle (lateral) deltoid, which forms the rounded cap on the side of your shoulder. This muscle is responsible for lifting your arm away from your body in the frontal plane, a movement called abduction. 

When well-developed, the middle deltoid creates the appearance of wider shoulders and contributes significantly to the coveted V-taper physique.

While the middle deltoid does the heavy lifting during lateral raises, this exercise also engages the anterior (front) deltoid as a secondary mover. 

The supraspinatus, one of the rotator cuff muscles, assists in the initial phase of the lifting motion, particularly in the first 15–30 degrees of abduction. The upper trapezius activates as a stabilizer, though ideally, you want to minimize excessive trap involvement.

Key Muscle Groups Engaged During Reverse Flys

Reverse flys target the posterior (rear) deltoid as the primary mover. This often-neglected portion of the shoulder sits at the back of your deltoid complex and works in conjunction with your upper back muscles. The rear delts play a crucial role in pulling movements, shoulder stabilization, and maintaining proper posture.

Reverse flys significantly engage the rhomboids and middle trapezius muscles. These upper back muscles are responsible for retracting your shoulder blades and supporting proper posture. 

The infraspinatus and teres minor, two rotator cuff muscles, also activate during this movement to help control the rotation of your shoulder joint. The complementary nature of these exercises becomes clear when examining their muscle activation patterns. 

Build Complete Shoulder Development with SOLE

SOLE's adjustable dumbbells and versatile weight bench provide everything needed for complete shoulder development.

SOLE's SW180 Adjustable Dumbbells provide the perfect foundation for both lateral raises and reverse flys. With 16 weight options from 5–80 pounds, you can start with appropriate lighter weights to perfect your reverse fly form, then quickly adjust to heavier resistance for lateral raises within the same workout session.

The SW116 Weight Bench transforms your reverse fly training by enabling the incline chest-supported variation, which eliminates lower back strain while maximizing rear deltoid isolation. 

The SOLE Equipment Mat provides essential stability for standing variations of both exercises. The superior grip prevents foot slipping during standing lateral raises and bent-over reverse flys, while the cushioning protects your lower back during the hinged position required for bent-over reverse fly variations.

The SW111 Olympic Barbell supports compound shoulder movements like overhead presses that complement your isolation work, while the SOLE+ App includes structured shoulder training programs that systematically progress both lateral raises and reverse flys with proper form cues and periodization strategies.

Check out SOLE's strength equipment today!

Frequently Asked Questions (FAQs)

Can I do lateral raises and reverse flys on the same day?

Yes, you can certainly perform both exercises in the same workout session. In fact, this approach often works well for creating balanced shoulder development. For a shoulder-focused workout, you might start with compound movements like overhead presses, then include both lateral raises and reverse flys as accessory exercises. 

Which exercise is better for fixing rounded shoulders?

Reverse flys are significantly more effective for correcting rounded shoulders and forward head posture. This postural issue, common among desk workers and those who spend long hours looking at screens, involves weakness in the posterior chain muscles that reverse flys directly target. 

Do lateral raises build wider shoulders than reverse flys?

Yes, lateral raises are more effective for building shoulder width because they directly target the middle deltoid, which creates the side projection of your shoulders. When looking at someone head-on, well-developed middle deltoids create that coveted broad-shouldered appearance. 

What weight should beginners use for these exercises?

Beginners should start conservatively with both movements, focusing on perfect form before adding weight. For lateral raises, most beginners should start with 5–10 pound dumbbells for women and 10–15 pounds for men. 

For reverse flys, even lighter weights are appropriate, often 2–3 pounds less than what you use for lateral raises, as the rear deltoids are typically weaker than the middle deltoids. 

How does SOLE equipment support both lateral raise and reverse fly training?

SOLE's SW180 Adjustable Dumbbells provide the ideal solution for both exercises with 16 weight options from 5–80 pounds, allowing precise progression as your lateral raise and reverse fly strength develops. The quick-adjust dial system enables seamless transitions between the typically heavier weight used for lateral raises and the lighter weight needed for reverse flys within the same workout. 

The SW116 Weight Bench is essential for incline reverse fly variations, providing adjustable positions that support your chest during the movement and eliminate lower back strain.