Pec-Deck vs. Machine Flye

The pec-deck flye is a very popular machine exercise that isolates the chest. What changes when you swap this version with the old-school machine flye?

November 13, 2012

By Jimmy Pena, MS, CSCS | Contributing Director of Strength and Conditioning

The Common Pec-Deck

A standard single-joint move for chest is the pec-deck flye, where you sit erect on the bench and grasp the handles at chest level. Your elbows are up and slightly bent with your arms parallel to the floor. You bring your hands together in front of you as if you were hugging a barrel or tree.

Traditional Pec-Deck

Single-joint exercises like the pec-deck flye are typically done after heavy multijoint moves (at various angles) in your chest workout. The pec deck allows you to destroy your outer and inner chest fibers with pinpoint accuracy. For variety, you can also do this move at the beginning of your routine to pre-exhaust the chest. Most always done last, it’s a great way to flush and pump the fibers of the pectoral muscles.

Make This Change

Machine Flye

On the surface, these two single-joint chest moves appear similar. However, when you sit in an older machine flye and place your arms on the pads, you must angle your arms at 90 degrees with just your upper arms parallel to the floor. As you push on the pads to bring your arms in front of you, you realize that you can bring your elbows almost completely together, which you can’t do using the pec deck. That means the range of motion and the tension you can place on your chest far exceeds that of the popular pec deck.

Not buying it? Go ahead and try it sitting on your sofa or at your desk. Raise your elbows, bring them together in front of your face and squeeze. Then try the alternate arm position similar to the pec deck, as if you’re hugging a barrel. Which one do you feel more? Exactly.

Get the Benefits of Both

No single machine will give you complete fullness in your chest, so be sure to include both versions in your training, alternating from one workout to the next. While the more common pec deck is great at isolating both the outer and inner pectoral fibers, the old-school machine flye affords incredible tension through a greater range of motion.