Pec Deck Fly
The pec deck fly is a chest (pectorals) fly done with a machine. It also works the shoulders (deltoids). On weyt.ai it counts toward Balance as Chest (minimum 10 sets per 30 days) and toward Gains at the weight you log.
At a glance
| Muscle group | Chest |
|---|---|
| Primary muscles | chest (pectorals) |
| Secondary muscles | shoulders (deltoids) |
| Equipment | Machine |
| Logged as | Reps per set |
| Gains scoring | Load-scored |
| Balance group | Chest · minimum 10 sets per 30 days |
| Strength standards | none (standards exist for barbell and dumbbell lifts with published norms) |
How weyt.ai scores it
- Balance: every logged set counts toward the Chest group, which needs at least 10 sets per 30 days for full credit.
- Gains: load-scored. Your best working set each session feeds an estimated one-rep max and a volume trend per lift over 8 weeks.
- Routine: any session that includes it counts toward your weekly target, the 4-week consistency window and your streak.
Scoring is deterministic code, not AI: the same sets always give the same Weyt Score. Read the method on the about page.
Also called
pec deck, machine fly, butterfly machine, machine chest fly, seated fly machine
Log it under any of these names and weyt.ai resolves it to the same exercise, so your history and progression never split across spellings.
Related chest exercises
- Dumbbell Chest Fly
- Incline Dumbbell Fly
- Cable Chest Fly
- Machine Chest Press
- Smith Machine Bench Press
- Barbell Bench Press
Everything else that counts as chest
Incline Barbell Bench Press · Decline Barbell Bench Press · Dumbbell Bench Press · Incline Dumbbell Press · Decline Dumbbell Press · Cable Chest Press · Resistance Band Chest Press · Chest Squeeze and Hold · Push-Up · Wide Push-Up · Decline Push-Up · Incline Push-Up · Weighted Push-Up · Archer Push-Up · Dip · Weighted Dip