The Single Arm Machine Rear Delt Fly is a beginner machine rear-delt fly that primarily trains the shoulders, with the back assisting. It is useful for training the rear delts and upper back through horizontal shoulder abduction.
Primary muscles
shoulders
Secondary muscles
back
Equipment
machine
Difficulty
beginner
TARGET AREA
Muscles worked
Primary muscles
shoulders
Secondary muscles
back
THE MOVEMENT
How to perform
Adjust the machine so the working arm can move horizontally without the shoulder shrugging.
Brace the torso against the support and hold one handle.
Sweep the working arm out and back by moving through the rear shoulder.
Return slowly, complete the set, then switch sides.
IRONYOU / CORE
Core cues
Keep the torso or pelvis stable and match the range of motion between sides.
Lead with the elbows and keep the movement controlled.
Use a range that keeps tension on the rear delts instead of forcing the hands too far behind you.
STAY SHARP
Common mistakes
Rotating or shifting the torso/pelvis to make the working side easier.
Using torso momentum to move the load.
Shrugging and letting the upper traps dominate.
YOUR PROGRESS
Your strength
Use your best set to calculate your current IronYou rank and see what comes next.
IRONYOU RANK CALCULATOR
127 exercises. One ladder. Your first rank is free.
Published reference points from the production IronYou rank system.
IronYou has 13 strength ranks: Copper I–III → Silver I–III → Gold I–III → Titanium I–III → IRON. IRON is the highest IronYou rank. The public standards tables show the estimated 1RM required to enter Silver I, Gold I, Titanium I, and IRON. Standards vary by sex and bodyweight.
Logged load: load for the working side. Public value: per logged side.
Single Arm Machine Rear Delt Fly Strength Standards — Male
Male
Published estimated 1RM thresholds by bodyweight. Load is recorded as per logged side.
Single Arm Machine Rear Delt Fly estimated 1RM strength standards by bodyweight and IronYou rank — Male.
Bodyweight (kg)
Silver I
Gold I
Titanium I
IRON
50 kg
5 kg
6.7 kg
8.3 kg
11.7 kg
60 kg
5.6 kg
7.4 kg
9.2 kg
12.9 kg
70 kg
6.1 kg
8 kg
10 kg
14.1 kg
80 kg
6.5 kg
8.6 kg
10.7 kg
15.1 kg
90 kg
6.9 kg
9.1 kg
11.4 kg
16.1 kg
100 kg
7.3 kg
9.6 kg
12 kg
16.9 kg
110 kg
7.6 kg
10.1 kg
12.5 kg
17.7 kg
120 kg
7.9 kg
10.5 kg
13 kg
18.3 kg
Single Arm Machine Rear Delt Fly Strength Standards — Female
Female
Published estimated 1RM thresholds by bodyweight. Load is recorded as per logged side.
Single Arm Machine Rear Delt Fly estimated 1RM strength standards by bodyweight and IronYou rank — Female.
Bodyweight (kg)
Silver I
Gold I
Titanium I
IRON
40 kg
2.1 kg
2.8 kg
3.5 kg
4.9 kg
50 kg
2.8 kg
3.7 kg
4.6 kg
6.5 kg
60 kg
3.2 kg
4.3 kg
5.3 kg
7.5 kg
70 kg
3.5 kg
4.6 kg
5.8 kg
8.1 kg
80 kg
3.7 kg
4.9 kg
6.1 kg
8.5 kg
90 kg
3.8 kg
5 kg
6.2 kg
8.8 kg
100 kg
3.8 kg
5.1 kg
6.3 kg
8.9 kg
IronYou-specific standard; resistance can vary between machines/equipment.
Values are estimated 1RM thresholds required to enter the named IronYou major rank tier.
Standards are derived from the production IronYou Rank V1 model.
IronYou-specific standard; resistance can vary between machines/equipment.
KEEP EXPLORING
Variations
Related variations: Dumbbell Rear Delt Fly, Dual Cable Rear Delt Fly, and Single Arm Dumbbell Rear Delt Fly.
Use single-side work to match control between sides, or a bilateral version when you want both sides working together.
EARLY ACCESS
Track Single Arm Machine Rear Delt Fly in IronYou.
Keep your last session, progress and next target with you when you train.