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Rear delt flys and face pulls are popular exercises for strengthening the posterior (rear) delts. When choosing to perform one over the other, there are subtle differences that you should be aware of.
The rear delt fly is an isolation exercise for the posterior delts while the face pull is a compound exercise that works the biceps, upper back, and shoulders. This is because rear delt flys are performed via the shoulder joints alone, while face pulls use the shoulder and elbow joints.
Not sure which one you should incorporate into your shoulder training? No worries! Read on for the list of differences in terms of muscle emphasis, equipment variability, and more.
Table of Contents
1. Rear Delt Flys Are a Single-Joint Exercise
Rear delt flys are a single joint exercise, which is the differentiating factor from face pulls in terms of muscle involvement. They are a single joint movement because there is a single pair of joints actively working to perform the fly, which is the shoulders.
During the concentric phase, the upper arms are lifted behind your back. This is called horizontal extension or transverse abduction and is primarily performed by the rear delts.
| Joint Used During Rear Delt Flys | Joint Function |
|---|---|
| Shoulder | Horizontal Extension/Abduction |
2. Face Pulls Are a Multi-Joint Exercise
Unlike rear delt flys, face pulls require two joints to be active. These are the shoulders and elbows. The actions of the shoulders are still responsible for the bulk of the movement, especially to work the rear delts.
The rear delts work to pull the upper arms behind the body while also rotating the forearms upward during face pulls. These functions of the shoulder joint are known as horizontal extension and external rotation, respectively.
The elbows are also involved in pulling the cable toward your forehead or chin depending on what angle your cable is set at. This active bending of the elbows is called flexion, which engages the biceps.
| Joints Used During Face Pulls | Joint Functions |
|---|---|
| Shoulders | Horizontal Extension, External Rotation |
| Elbows | Flexion |
3. Rear Flys Isolate Rear Delts, Face Pulls Don’t
Although face pulls are often used for rear delt isolation, they are a compound exercise. This means that multiple muscles engage synergistically to perform the movement effectively and safely.
Face pulls are not the best isolation exercise for the rear delts because they engage the upper back and biceps as well. This restricts the amount of tension being placed exclusively on the rear delts throughout the full range of motion.
Regardless, doing face pulls on back or shoulder days is a time-efficient way to train the traps, rhomboids, and rear delts simultaneously. However, if your rear delts are a weak point, consider exercises that solely use a horizontal extension.
EMG research shows isolation exercises such as the rear delt fly to be the gold standard for engaging these muscles. That’s why top strength coach Bret Contreras is adamant about utilizing this type of movement.
Isolation exercises for the rear delts kick the shit out of compound movements in terms of EMG activity.
Bret Contreras
4. Face Pulls Target the Rotator Cuffs More
The rotator cuff muscles are responsible for stabilizing the shoulder during movement.
There are two active shoulder functions (external rotation and extension) during face pulls, compared to one with rear delt flys. This generates greater activation of the rotator cuff muscles as a whole during face pulls.
5. Face Pulls Dynamically Rotate the Shoulders
When performing face pulls the shoulders are rotated internally in the starting position while the arms are straight. They then externally rotate as you pull the handle towards your face.
This is why the rotator cuff muscles, specifically the infraspinatus and teres minor are more active with face pulls than with rear delt flys.
6. Rear Delt Flys Statically Rotate the Shoulders
Whether you use an overhand or neutral grip to perform rear delt flys, the shoulders do not actively rotate. Instead, they are held in a rotated position as you raise and lower the upper arms.
For example, when using an overhand grip the shoulders will be internally rotated the entire time. A neutral grip (palms facing each other) on the other hand, puts the shoulders in a more externally rotated position.
Either way, this rotation is not active since it’s being isometric throughout the range of motion.
7. Face Pulls Are Performed Standing Upright
Face pulls are almost always performed while standing with the torso vertical to the floor. Although this isn’t the golden rule, it is the norm. They are rarely performed from a horizontal torso position like a rear delt fly is.
The torso angle doesn’t matter too much for face pulls since there is going to be constant tension as long as you use the proper motions.
8. Rear Flys Can Be Performed Bent-Over or Upright
The torso position is usually more dynamic with rear delt flys. For instance, there are machines where you can do them bent-over while others like the reverse pec deck fly require the torso to be vertical.
Similarly, cables allow you to set the pulleys high and do them upright or set the pulleys low and bend over. Choose the angle you feel most comfortable for executing the behind-the-body arm movement.
9. Face Pulls Hit The Traps More Than Rear Flys
The shoulder blades squeeze together more during face pulls than they do during rear delt flys. This motion is called scapular retraction, and it recruits the middle traps and rhomboids (upper back muscles).
Granted you perform face pulls correctly, there is also scapular depression, but not so much during rear delt flys. This motion works the lower portion of the trapezius.
10. Face Pulls Engage the Biceps, Rear Flys Do Not
Because the elbows actively bend during face pulls there will be some bicep involvement. My biceps tend to be overactivated during face pulls, so I prefer rear delt flys for pure rear deltoid stimulation.
11. Rear Delt Flys Offer More Equipment Variety
Face pulls are limited to a cable machine with a rope attachment or resistance bands. You can do them with dumbbells as well but the resistance curve isn’t optimal for maintaining muscle tension.
Furthermore, rear delt flys are often performed with dumbbells, cables, resistance bands, pec decks, or lateral raise machines.
In the grand scheme, face pulls and rear flys are effective shoulder exercises in their own right. Prioritize face pulls to maintain or improve rotator cuff health. Focus on rear delt flys to maximize the development of your rear delts.
And if you’re interested in doing both, you can! Read my article for a shoulder workout with rear delt flys (bent-over lateral raises) and face pulls.
