Reverse Pec Deck (Butterfly)

How to perform it

1. 1Preparation and positioning. Adjust the seat, pad, pulley, handle, and starting range so the working joints align comfortably. Secure attachments and keep the body out of the cable/lever path.
2. 2Starting position. Set the upper arms in the prescribed fly arc with a small, consistent elbow bend, ribcage controlled, and feet stable.
3. 3Concentric phase. Bring the upper arms toward/across the torso along the chosen cable or machine arc without turning the rep into an elbow press.
4. 4End position / lockout. Reach the same hand/upper-arm marker without shoulder roll, cable collision, or forced crossing.
5. 5Eccentric phase. Return under control to the same pain-free start marker, maintaining handle alignment and preventing the stack from crashing.
6. 6Breathing and bracing. Exhale through the shortening/pressing phase and inhale during the controlled return while keeping the torso supported.
7. 7Valid rep. A rep uses the same setup and range, keeps the stack controlled, and contains no torso lift, shoulder roll, momentum, or unplanned assistance.

Common mistakes

• Moving the trunk instead of the target joint

  Fix: Reduce the load and keep the torso and prescribed upper-arm position fixed.

• Changing the elbow angle

  Fix: Set a small, consistent bend—or the defined flexion angle—and preserve it through the rep.

• Shrugging to gain range

  Fix: Keep the neck long and stop where the shoulder/scapular path remains controlled.

• Dropping the eccentric

  Fix: Return to the same start marker slowly without letting the stack or weight take over.

Safety

• Current shoulder symptoms require an individually tolerated arm path and range; do not force a generic elbow angle or end position through pain.
• Do not force a deep shoulder-extension or horizontal-abduction stretch; define the bottom by controllable, symptom-free shoulder range.
• Adjust the machine to the user, verify the selector pin/attachment and safety stops, and keep hands, clothing, and other people clear of the moving lever, cable, and stack.

Progressions & alternatives

• regressionChest-supported Dumbbell Reverse Fly— Reduce strength, balance, or coordination demand while rehearsing the key pattern before returning to Reverse Pec Deck (Butterfly).
• progressionSingle-arm Reverse Pec Deck— Increase load, range, instability, or skill demand after Reverse Pec Deck (Butterfly) is repeatable through the planned volume with reserve and no technique drift.
• alternativeDumbbell Reverse Fly— Train a similar primary pattern with a different stability, equipment, or joint-loading profile when Reverse Pec Deck (Butterfly) is impractical or poorly tolerated.