Pec deck: how to do it
Main muscles: Middle chest. Helpers: Upper chest, Front delts (anterior deltoid). Below: step-by-step form, common mistakes, a muscle map, reps and rest, and what to swap it for.
Equipment
Machine
Reps
10–15
Rest
75 s
Muscle group
Chest
How to do it
- Set the seat so the handles are at mid-chest height.
- Bring the arms together smoothly and hold for a second at the end.
- Open slowly to a stretch that does not hurt the shoulder.
Common mistakes
Opening too far back, jerking, lifting the back off the pad.
Muscles worked
primary·secondary
- Primary
- Middle chest
- Secondary
- Upper chest, Front delts (anterior deltoid)
A secondary muscle gets roughly half the stimulus of a set — that is also how the log’s stats count it.
Alternatives: similar exercises
Seated chest press
Machine · Middle chest
Bench press
Barbell · Middle chest, Lower chest
Incline bench press
Barbell · Upper chest, Front delts (anterior deltoid)
Dumbbell fly
Dumbbells · Middle chest
Dumbbell bench press
Dumbbells · Middle chest
Incline dumbbell press
Dumbbells · Upper chest, Front delts (anterior deltoid)
Log your sets — the app suggests the next weight
GymAssist tracks the load on each of 40 muscles, paints it on a body map and uses double progression to tell you when to add weight.
Free forever for the first 500