How to Do the Butterfly at the Gym

The butterfly is one exercise that will strengthen and lift your chest.

Creatas/Creatas/Getty Images

The butterfly, also called the pec deck, pec deck fly, or chest fly, is an isolation exercise that specifically targets your chest muscles. Benefits of a strong chest include more upper-body power and strength, resulting in better athletic performance, as well as more fat burned. You can use the butterfly machine at the gym, or dumbbells and a bench, to do butterflies.

Using the Butterfly Machine


Sit on the butterfly machine with your front facing away from it and your back flat up against the padding. Your feet should be flat on the floor. Lower or raise the seat if necessary.


Adjust the machine as needed so that your upper arms are parallel to the floor when you grasp the handles.


Contract your chest muscles to push the handles toward each other for the count of 2 as you exhale. When the handles are together, hold for one second. Then, slowly release and return to your starting position for the count of three or four as you inhale.


Repeat for eight to 12 reps, and do up to three sets. For best results, the amount of weight you choose should be too heavy for you to be able to do more than 12 reps without cheating or resting, according to the American Council on Exercise.

Using Dumbbells


Hold two dumbbells and lie on a bench on your back. Hold them together directly above your chest with your arms almost straight. Rotate your shoulders inward so that your elbows are facing out toward your sides.


Lower your dumbbells to your sides for the count of three or four until your arms are parallel to the bench.


Pull your dumbbells back together for the count of two. Repeat for eight to 12 reps for up to three sets.

Things Needed

  • Access to a gym


  • Allow your chest muscles to get at least 48 hours to recover and rebuild before you do the butterfly or another chest exercise again.