Reverse Fly: Build Your Rear Delts
The reverse fly targets the often-neglected posterior deltoid and upper back muscles, improving shoulder health, posture, and the three-dimensional look of your shoulders.
Proper Form
Hinge at the hips with a slight bend in your knees, torso nearly parallel to the floor. Hold a dumbbell in each hand with arms hanging straight down, palms facing each other.
With a slight bend in your elbows, raise both dumbbells out to the sides in a wide arc until your arms are roughly parallel with the floor.
Squeeze your shoulder blades together at the top of the movement and hold for one second.
Lower the dumbbells slowly back to the starting position, resisting gravity on the way down.
Keep your head neutral and torso stable. Avoid swinging your body or using momentum to lift the weights.
Calories Burned Calculator
Reverse Fly on GLP-1 Medications
Rear deltoid and upper back training is critical during GLP-1-mediated weight loss to prevent the forward-rounded posture that can develop as supporting musculature decreases. The reverse fly strengthens the posterior shoulder chain, improving posture and shoulder joint stability. Because it uses light weights and focuses on slow, controlled movement, it is well-suited for individuals with reduced energy levels or appetite from GLP-1 therapy. It also helps maintain the appearance of broader shoulders as body fat decreases.
Variations
- 1Seated bent-over reverse fly for more stability
- 2Cable reverse fly at face height for constant tension
- 3Machine reverse fly (pec deck reversed) for guided movement
- 4Band pull-apart as a warm-up or high-rep finisher
Why Rear Delts Matter
Most people over-develop the front (anterior) deltoid through pressing movements while neglecting the rear (posterior) deltoid. This imbalance pulls the shoulders forward into a rounded posture and increases the risk of shoulder injuries, particularly impingement. The posterior deltoid also plays a critical role in the deceleration phase of throwing, pulling, and overhead movements. Training your rear delts with exercises like the reverse fly corrects this imbalance, improves shoulder health, and creates the rounded, three-dimensional shoulder look that distinguishes a trained physique.
Programming Reverse Flyes
The rear deltoid responds best to high-rep, moderate-weight training with a focus on the contraction. Perform 3-4 sets of 12-20 reps. Because the posterior deltoid is a small muscle group, you do not need heavy weights. Most men will use 10-20 pound dumbbells, and most women will use 5-12 pounds. Include reverse flyes in every shoulder or upper-back workout, or use them as a warm-up before pressing movements to pre-activate the rear delts and improve pressing form.
- Hypertrophy: 3-4 sets x 12-20 reps with 1-second hold at the top
- Great as a warm-up or finisher for any upper-body session
- Can be performed daily at light loads for posture correction
Getting the Mind-Muscle Connection
The reverse fly requires a strong mind-muscle connection to avoid turning it into a trap-dominant movement. Focus on initiating the movement by pulling your elbows outward rather than squeezing your shoulder blades first. If your upper traps are doing most of the work, you will feel the burn between your shoulder blades rather than in the back of your shoulders. Lowering the weight and adding a pause at the top can help re-establish the correct activation pattern. Face pulls at a cable station can also be used to learn the posterior deltoid contraction before progressing to reverse flyes.
Muscles Worked
Exercise Disclaimer
This content is for informational purposes only and does not replace professional instruction. Consult a qualified trainer or healthcare provider before starting any exercise program. Individual calorie burn varies based on fitness level, intensity, and body composition.
Frequently Asked Questions
Lighter than you think. The posterior deltoid is a small muscle, and the leverage in the bent-over position is disadvantageous. Most trained men use 12-20 pound dumbbells, and most women use 5-12 pounds. If you cannot perform the movement without swinging your body, the weight is too heavy. The quality of the contraction matters far more than the number on the dumbbell.
Both target the rear deltoid, but the movement patterns differ. The reverse fly is a horizontal abduction movement in a bent-over position. Face pulls are performed at a cable station with external rotation at the top. Face pulls tend to involve more of the rotator cuff and middle traps. Both are excellent and should be included in a complete shoulder program.
With a MET value of 3.0, the reverse fly burns approximately 3-4 calories per minute for a 180-pound person. It is a low-intensity isolation movement, so calorie burn is minimal. Its value lies in shoulder health, posture improvement, and muscle development rather than energy expenditure.
Either works, or both. The posterior deltoid is involved in pulling (back) and is part of the shoulder complex. Many programs include them on both days with different variations. If you must choose one, place them on your shoulder day to balance the pressing volume with pulling work.
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