The Single Arm Machine Chest Fly is a beginner machine fly that primarily trains the chest, with the shoulders assisting. It is useful for training the chest through horizontal adduction with less triceps involvement than a press.
Primary muscles
chest
Secondary muscles
shoulders
Equipment
machine
Difficulty
beginner
TARGET AREA
Muscles worked
Primary muscles
chest
Secondary muscles
shoulders
THE MOVEMENT
How to perform
Adjust the seat so the working handle lines up comfortably with the chest.
Set the torso against the pad and keep a soft bend in the working elbow.
Bring the working arm inward in a controlled arc without rotating the torso.
Return slowly to a comfortable chest stretch, then switch sides after the set.
IRONYOU / CORE
Core cues
Keep the torso or pelvis stable and match the range of motion between sides.
Move through a chest-focused range you can control without forcing the shoulders too far back.
Think about bringing the upper arms together rather than just moving the hands.
STAY SHARP
Common mistakes
Rotating or shifting the torso/pelvis to make the working side easier.
Going so deep that the shoulders lose a stable position.
Using momentum or too much load and turning the movement into a press.
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 Chest Fly Strength Standards — Male
Male
Published estimated 1RM thresholds by bodyweight. Load is recorded as per logged side.
Single Arm Machine Chest Fly estimated 1RM strength standards by bodyweight and IronYou rank — Male.
Bodyweight (kg)
Silver I
Gold I
Titanium I
IRON
50 kg
10.1 kg
13.3 kg
16.6 kg
23.4 kg
60 kg
11.1 kg
14.8 kg
18.4 kg
25.9 kg
70 kg
12.1 kg
16.1 kg
20 kg
28.2 kg
80 kg
13 kg
17.2 kg
21.4 kg
30.2 kg
90 kg
13.8 kg
18.3 kg
22.8 kg
32.1 kg
100 kg
14.5 kg
19.3 kg
24 kg
33.8 kg
110 kg
15.2 kg
20.1 kg
25 kg
35.3 kg
120 kg
15.8 kg
20.9 kg
26 kg
36.7 kg
Single Arm Machine Chest Fly Strength Standards — Female
Female
Published estimated 1RM thresholds by bodyweight. Load is recorded as per logged side.
Single Arm Machine Chest Fly estimated 1RM strength standards by bodyweight and IronYou rank — Female.
Bodyweight (kg)
Silver I
Gold I
Titanium I
IRON
40 kg
4.5 kg
5.9 kg
7.4 kg
10.4 kg
50 kg
6 kg
7.9 kg
9.8 kg
13.9 kg
60 kg
6.9 kg
9.1 kg
11.4 kg
16 kg
70 kg
7.5 kg
9.9 kg
12.3 kg
17.4 kg
80 kg
7.8 kg
10.4 kg
12.9 kg
18.2 kg
90 kg
8.1 kg
10.7 kg
13.3 kg
18.7 kg
100 kg
8.2 kg
10.9 kg
13.5 kg
19.1 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: Cable Chest Fly, Flat Dumbbell Chest Fly, and Incline Dumbbell Chest 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 Chest Fly in IronYou.
Keep your last session, progress and next target with you when you train.