Pulling: back and shoulders

Rear delt fly

Muscles worked: Rear shoulders · upper back

The rear delt fly trains the back of your shoulders and the muscles between your shoulder blades. It’s a small lift, so keep the weight light and the movement slow.

You’ll also hear it called a reverse fly, back fly or rear delt flye. They’re all the same move.

Muscles worked

The main mover is the rear (posterior) deltoid, the back third of your shoulder muscle. The middle and lower trapezius and the rhomboids help hold your shoulder blades steady, and the small rotator cuff muscles at the back of the shoulder chip in too. Most gym programmes have plenty of pressing for the front of the shoulders, so a pulling move like this one helps balance things out.

How to do a rear delt fly

1. Pick light dumbbells. Go lighter than you think. Most people start with 2 to 5 kg in each hand, because the muscles at the back of the shoulder are small.
2. Hinge forward. Stand with your feet hip-width apart and knees soft. Push your hips back until your chest is at about 45 degrees or lower, with your back flat and the dumbbells hanging under your shoulders, palms facing each other.
3. Set your arms. Put a slight bend in your elbows and keep it the same for the whole set. Keep your neck long and look at the floor a little in front of you.
4. Raise out to the sides. Sweep your arms out and up in a wide arc, leading with your elbows, until your arms are level with your body. Think about moving your hands away from each other rather than pulling them up.
5. Pause. Hold the top for a second without shrugging. Breathe out as you lift.
6. Lower slowly. Take 2 to 3 seconds to lower the weights to just short of hanging, then start the next rep.

Form cues

• Hinge from your hips with a flat back and soft knees.
• Lead with your elbows and think “wide”, not “up”.
• Keep your shoulders down, away from your ears.

Common mistakes

• Swinging the weights up. If your body rocks to get the dumbbells moving, they’re too heavy. Drop the weight and count one second up, three down.
• Shrugging. If you feel it mostly in your neck and the tops of your shoulders, you’re shrugging. Keep your shoulders down, away from your ears, and go lighter.
• Bending your elbows as you lift. Bending and straightening the arms turns it into a row. Lock in a soft bend at the start and keep it.
• Standing up during the set. Your chest creeps up as you tire and the work moves to your traps. Keep the same body angle, or use the chest-supported version below.
• Lifting past your body line. Going higher usually means arching your back or pinching your shoulder blades hard. Stop when your arms are level with your body.
• Rounding your lower back. Keep your back flat in the hinge. If that’s hard, sit or lie on a bench instead.

Variations

Same movement, different kit. Pick whichever you have, or whichever lets you keep the best form. For four more moves that train the back of your shoulders, see our post on rear delt exercises.

Bent-over dumbbell rear delt fly

The standing version in the pictures at the top of this page, and the one the steps above describe. Hinge from your hips until your chest is at about 45 degrees or lower, with your back flat, knees soft and the dumbbells under your shoulders. Keep a soft bend in your elbows, sweep your arms out to the sides until they’re level with your body, then lower slowly. If your lower back tires or your chest starts creeping up, switch to the lying or seated version.

Lying (chest-supported) dumbbell rear delt fly

Lie face down on a bench set to 30 to 45 degrees and let the dumbbells hang. The bench stops you swinging or standing up, so it’s the easiest version to keep strict and a good first choice in the gym.

Seated bent-over rear delt fly

Sit on the end of a bench, lean your chest towards your thighs and fly from there. Handy if your lower back gets tired in a standing hinge.

Cable rear delt fly

Set two pulleys at shoulder height, take the left handle in your right hand and the right handle in your left, and open your arms out wide. The cables keep tension on all the way through.

Machine reverse fly (reverse pec deck)

Face the pad, set the seat so the handles are level with your shoulders and push the handles back in an arc. The machine guides the path, so it’s easy to learn and easy to add weight in small steps.

Band reverse fly

Hold a light resistance band in front of you at shoulder height and pull it apart until your arms are out to the sides. Good at home or as a warm-up before pressing. The band pull-apart page has the details.

Easier and harder versions

Easier

• The lying, chest-supported version, so your body can’t swing.
• A light band instead of dumbbells.
• One arm at a time, with your other hand resting on a bench.

Harder

• Pause for two seconds at the top of each rep.
• Take three seconds to lower.
• Move to the cable version, which keeps the tension on all the way through. Add weight last, in the smallest jumps you can.

Sets and reps for beginners

• 2 to 3 sets of 12 to 15 reps, finishing each set feeling you could do two or three more good reps.
• Rest 60 to 90 seconds between sets.
• Two or three times a week, near the end of an upper-body or pull session, or as a light warm-up before shoulder pressing.
• Move up slowly. When you can do 20 clean reps on every set, go up by the smallest jump you can. Writing your reps down each time makes this easy to track.

Rear delt fly questions

Where it appears in the member plans

Beginner Reset uses it for 2 sets of 12 on the hips, back and shoulders day. Fat-Loss Foundations and Strength Builder use 3 sets of 12 to 15, on the shoulders, arms and upper back day and the back and biceps day.