The butterfly press, or fly, is an exercise that strengthens the pectoral (chest) muscles and is typically performed with a weight machine or a cable weight machine at a health club. You might have instances, however, in which you want to perform this movement with free weights instead of a larger machine. Strengthening the chest is important for everyday movements and for improving your overall physical fitness.
Select the type of free weight you wish to use. Dumbbells, resistance bands and kettlebells are all examples of weights with which you can perform this exercise. Choose a light weight of 5 to 10 lbs. and gradually increase the weights as you build muscle.
Lie on a bench with your back and head flat and place your feet firmly on the floor. Start with the weights straight over your chest with a slight bend in your elbows. Face your palms toward each other. This is the starting position for the exercise.
Lower the weights slowly outward to the sides of your body. Go as low as you can but stop when your arms are parallel to the ground. Hold in the lowered position for one second, then raise the weights slowly back over your body to the starting position. Maintain the same arc in your arms when lifting and lowering.
Complete the appropriate number of sets and repetitions. If you wish to build more muscle, use a slightly heavier weight and complete three to five sets of six to eight repetitions. If your goal is to build more muscular endurance, use a lighter weight and complete two to four sets of 10 to 12 repetitions.