Single-Arm Pec Deck

One-arm machine fly: each side works separately.

• Isolation
• Machine
• Beginner

How to do it

• One arm at a time with the elbow at chest height and the torso still
• Keep a fixed bend in the elbows throughout the arc
• Open until you feel the chest stretch and bring the hands together squeezing

Sets, reps and tempo

Ranges: 12–20 reps · 0–1 RIR

Tempo: Bring together for 1 s, squeeze 1–2 s, open for 2–3 s resisting

Common mistakes

• Bending and straightening the elbows like a press
• Twisting the torso to close further

Muscles worked

Primary

• Chest

Alternatives

• Pec Deck
• Chest Fly / Pec Deck
• Cable Crossover