Machine Fly (Pec Dec)
Auto DetectedMachine-based isolation movement that targets the pectoralis major to build chest hypertrophy and strength; commonly scaled by adjusting seat height or weight.
About Exercise
Equipment
Pec Dec Machine
Difficulty
1/5 • Beginner
Primary Muscle Groups
Chest
Secondary Muscles
Abs
Popularity Score
8
Goals
Training Style
Setup Requirements
Requires Rack
No
Requires Bench
No
Requires Spotter
No
Space Needed
Small
Noise Level
Low
Muscle Breakdown
View Muscle MapChest
10/10Mid Chest, Upper Chest
Shoulders
6/10Anterior Delts
Abs
3/10Programming
Typical Rep Range
8-15 reps
Rest Between Sets
60-90 seconds
How to Perform
Adjust the seat height so the handles align with your mid-chest. Sit with your back flat against the pad and grasp the handles with elbows slightly bent.
- Exhale and bring the handles together in front of your chest.
- Squeeze your chest muscles hard at the center position.
- Inhale and slowly return the handles to the starting position.
- Stop before the weights touch the stack to maintain tension.
- Keep a slight bend in your elbows throughout the movement.
Coaching Tips
Form Cues
- Squeeze chest
- Keep elbows fixed
- Back against pad
- Control the negative
- Don't shrug
Breathing
Exhale as you bring the handles together; inhale as you return to the starting position.
Tempo
3-1-1
Range of Motion
From arms extended out to the sides (elbows slightly behind torso) until handles touch or nearly touch in front.
Safety
Safety Notes
- Avoid hyperextending shoulders at the start
- Control the weight at all times
Spotting
Not recommended; use machine safeties or pin selection.
Common Mistakes
- Locking elbows
- Using momentum
- Shrugging shoulders
- Arching back excessively
When to Avoid
- Shoulder impingement
- Pectoral strain
Flexibility Needed
- Shoulder horizontal adduction
- Scapular stability
Build Up First
- Basic posture control
- Machine adjustment familiarity
Also known as
Pec Deck Fly, Butterfly Machine, Chest Fly Machine, Seated Machine Fly, Deck Fly
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