Machine Fly
A machine-based isolation exercise that targets the middle chest by bringing the arms together in a hugging motion. It uses a fixed path to provide constant tension on the pectorals while minimizing the need for balance and stabilization.
This exercise is excellent for hypertrophy, but volume management is key to preventing shoulder strain. The AI analyzes your RPE and total weekly pushing volume to ensure you are stimulating the chest without overtaxing the anterior deltoids. If you track shoulder discomfort or poor sleep quality, the app can recommend limiting the range of motion or swapping to a pressing variation to protect your joints while still driving progress.
Form Cues
- Adjust the seat so handles align with your mid-chest
- Keep a slight, fixed bend in your elbows throughout
- Squeeze your chest muscles hard when handles meet
- Control the weight slowly on the way back
- Keep your shoulder blades retracted against the pad
- Don't let the weight stack slam down between reps
- Don't straighten your arms completely at any point
- Don't hunch your shoulders forward near your ears
- Don't bring your elbows too far behind your torso
Common Mistakes
- Setting the seat too low or high
- Using excessive momentum to start the rep
- Hyperextending the shoulders on the return
- Pressing the weight instead of flying
- Lifting the head off the support pad
Muscles Worked
This exercise primarily isolates the sternal head of the pectoralis major (middle chest) through horizontal adduction. The anterior deltoids act as secondary movers to assist the motion, but the fixed path helps minimize their involvement compared to free weight variations.
Primary
Secondary
Get Personalized Coaching for Machine Fly
Don't guess your way through weights or workouts. Download Iridium for automatic, AI-powered coaching that adapts to your recovery and goals.