Comparison · Rear Delts
Cable Rear Delt Fly vs Reverse Pec Deck: Free Cable Arc or Fixed Machine Path?
Both open the arms wide against resistance that does not depend on gravity. One has you standing between two pulleys, steering each arm yourself; the other seats you against a pad and steers for you.
The verdict
The Cable Rear Delt Fly and the Reverse Pec Deck both keep the rear delts loaded through the whole sweep. The cable version is done standing on a free path, peaks with the arms widest and adds the infraspinatus; the machine fixes your chest and arm path and brings in the rhomboids. Pick the Reverse Pec Deck for simple, hard sets; pick the Cable Rear Delt Fly once the pattern is familiar.
Illustrations adapted from Everkinetic via workout-guide, CC BY-SA 4.0. Full credits.
At a glance
| Aspect | Cable Rear Delt Fly | Reverse Pec Deck |
|---|---|---|
| Equipment | Cable | Machine |
| Where | Gym | Gym |
| Level | Intermediate | Beginner |
| Back zone it leads | Rear Delts | Rear Delts |
| Muscles | Rear Delts, Infraspinatus | Rear Delts, Rhomboids |
| Typical work | 3 × 12–15 | 3 × 12–15 |
| Body position | Standing tall between two pulleys | Seated, chest pressed into a pad |
| Arm path | Free; each cable follows your arm | Locked to handles swinging on a pivot |
| Hardest point | Arms at their widest, out to the sides | Set by the machine’s lever, not your stance |
| Holding still | Your trunk and legs keep you steady | The pad does it; only the arms move |
| Second muscle credited | Infraspinatus joins at the wide end | Rhomboids join as the blades meet |
| Setup | Two pulleys matched, handles crossed over | Seat height and handle position only |
| Learning curve | Intermediate: staying tall with two free cables | Beginner: sit down and sweep |
What the Cable Rear Delt Fly and Reverse Pec Deck have in common
Both are rear delt flys driven by a weight stack rather than by gravity, so the arms are already working while they are still in front of the chest, unlike a dumbbell that weighs almost nothing at the bottom. In each, the elbows keep a slight bend, the upper arms sweep outward until they line up with the shoulders, and the rear delts do the moving. Both sit in the Rear Delts zone with Upper Back as a secondary zone, both default to 3 sets of 12 to 15, and both need a gym. Both also work best late in a session, with sets taken close to failure.
The differences that matter
Free arc against fixed arc. On the cable, nothing guides your hands but the cables, so each arm sweeps along whatever path your shoulder takes and can drift high, low or out of step if you let it. That same freedom lets the upper arm turn outward at the wide end, which is how the infraspinatus gets involved. The Reverse Pec Deck bolts the path down: the handles swing around a fixed pivot, both arms move as a pair, and there is no wandering off the arc.
Where the load is highest. Because the cables cross in front of you and pull toward the opposite side, their resistance is greatest when your arms are furthest apart, which is also where the rear delt is shortest. On the machine, the stack works through the lever arms rather than across your body, so the effort curve depends on the model more than on how you stand.
Who holds you still. Standing between pulleys, your trunk and legs must stay quiet while the arms open, and leaning back or rocking forward is the easy way to cheat a hard rep. The chest pad takes that job away. With the torso pinned, the shoulder blades are free to draw together at the finish, which is why the library lists the rhomboids for the machine rather than the infraspinatus.
Setup and learning. The cable version takes two pulleys at matching height, handles swapped across the body, and some practice to stay upright as the set gets hard; the library rates it intermediate for that reason. The machine needs a seat height and a handle position, and a beginner can take a demanding set on the first day.
When to pick the Cable Rear Delt Fly
Choose the Cable Rear Delt Fly when you can already feel your rear delts working and want a movement that loads them hardest at the widest point of the rep. It suits lifters who prefer to let each arm find its own line, and it trains the infraspinatus as the arms turn out at the end of the sweep. It is also the fallback when the pec deck is taken and a cable crossover is free. Keep the stack modest; every rep should end with your arms spread and your torso still, not leaning back to finish.
How to do the Cable Rear Delt Fly →
When to pick the Reverse Pec Deck
Choose the Reverse Pec Deck when you are newer to rear delt training, or when you want the simplest possible way to take a set to failure. The pad holds your chest, the handles set the path, and all that is left is the sweep, so there is little to learn and nothing to lose when the last rep grinds. It also brings the rhomboids in at the finish, adding a little mid-back work to what is mostly a shoulder movement. Adjust the seat so the handles line up with your shoulders before the first set.
How to do the Reverse Pec Deck →
Can you do both?
They cover different ends of the same job, so running both pays off when the rear delts need extra volume. Start with the Reverse Pec Deck for 3 sets of 12 to 15, pushing the last set to failure while you are fresh. Follow with 2 sets of 15 on the Cable Rear Delt Fly, lighter, pausing a beat with the arms wide. Across the week, one session can lead with the machine and the next with the cables. If Rear Delts is the zone BackMaxx scores lowest, keep both in until a re-scan shows it catching up.
Frequently asked questions
Is the cable rear delt fly better than the reverse pec deck?
Not better, just different. The Cable Rear Delt Fly loads the rear delts hardest at the widest point and lets each arm move freely, which also involves the infraspinatus. The Reverse Pec Deck locks your chest and path in place, making hard sets simpler and adding the rhomboids. For most lifters the better one is whichever you can progress steadily; rear delts that lag justify using both.
Should you cross the cables for a rear delt fly?
Yes. Take the left handle in your right hand and the right handle in your left, so each cable pulls across your body toward the far side. That line of pull puts the most resistance at the end of the sweep, with your arms out wide. Set both pulleys to the same height, around shoulder level or a little lower, and stand centered between them so both arms start with equal tension.
Which is better for beginners, the cable rear delt fly or the reverse pec deck?
The Reverse Pec Deck is the easier start. The library rates it beginner and the cable version intermediate, because the machine handles balance and path while the cable fly asks you to stay tall, keep the handles level and control two independent cables at once. Learn the sweep on the machine, then move to the cables once you can feel the rear delts working without the pad.
Can you do a cable rear delt fly one arm at a time?
Yes, and it is a useful variation. Stand side-on to a single pulley set at shoulder height or slightly lower, take the handle with the far hand, and sweep the arm across and out until it lines up with your shoulder. Working one side lets you watch each arm on its own and brace your free hand on the machine, though it doubles the time each set takes.
Let your back decide
BackMaxx scores six back zones and eight muscles from one photo. If your rear delts is what is behind, it builds the week around it — and picks between movements like these for you.
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