Bench Presses Vs. Flyes

Flyes and bench presses use different motions -- and usually different equipment -- to accomplish similar tasks. Both exercises strengthen your chest and shoulders, and both work a variety of arm muscles. Additionally, both activities have spawned numerous variations, allowing you to zero in on different parts of your chest. That versatility makes both exercises suitable for bodybuilders as well as for people seeking to strengthen their torsos.

  1. Muscles Worked

    • Standard bench presses and dumbbell flyes, performed on flat benches, both target the sternal head of your pectoralis major, which is your largest chest muscle. Both exercises also work your upper chest and front shoulder muscles. Additionally, the bench press hits your triceps -- while flyes don't -- and engages part of your biceps as a stabilizer. When you perform flyes, part of your biceps assists your movement while another part acts as a stabilizer. You’ll also engage a variety of other upper-arm and forearm muscles as stabilizers for flat-bench flyes.

    Comparison

    • Overall, the barbell bench press works your pectoral muscles harder than dumbbell flyes do, according to Muscle&Strength.com, because your pecs are engaged longer when you're bench pressing. If you decrease the pace of your flyes to increase the tension on your chest muscles, you risk straining your rotator cuff. Additionally, the American Council on Exercise (ACE) rates the barbell bench press as the most effective chest exercise. An ACE study concludes that inclined chest flyes provide just 69 percent of the pectoral muscle activation that the bench press offers.

    Form

    • To perform dumbbell flyes on a flat bench, lie face up with your feet on the floor. Hold a pair of dumbbells above your upper chest with your arms extended, your elbows slightly flexed and your palms facing each other. Inhale as you lower the weights slowly to your sides while maintaining the bend in each elbow. Exhale as you bring the dumbbells back up to the starting position. Begin the flat-bench barbell bench press in a similar body position as the dumbbell fly, but hold a barbell above your upper chest with your arms straight. Your hands should be positioned a bit wider than shoulder-width apart, with your palms facing away from your body. Inhale as you lower the bar until the barbell touches your middle chest with your elbows pointing down. Exhale as you lift the bar straight up to the starting position.

    Variations

    • Use an adjustable bench to shift the emphasis up or down your chest for either exercise. Perform bench presses or flyes on an incline bench, with your head higher than your knees, to target your upper chest muscles. Do either activity on a decline bench to emphasize your lower pectoral muscles. You can also do both exercises with different equipment. Perform a variety of standing, seated or lying flyes using a cable machine. You can perform bench presses with almost any exercise equipment you can think of, including dumbbells, cable machines and resistance bands. Dedicated flye and bench press machines also are available.

    Considerations

    • Consult your doctor before you begin any new exercise program. Stop performing bench presses or flyes if you feel any pain. Try to do at least three sets of eight to 15 repetitions of either exercise, depending on your fitness goals, using sufficient weight so your final reps are challenging. Use heavier weights and perform fewer repetitions if you’re trying to bulk up. Work with lighter weights and do more reps to gain muscular endurance. Don’t do chest flyes or bench presses on consecutive days. Use a spotter whenever you hold weights above your body.