Which Is Better for Dumbbell Flies: Standing or Lying on Your Back?

Variety is an important component of an exercise routine. It wards off both physical plateaus and mental boredom. You can perform the dumbbell fly exercise, which targets the chest muscles, in a standing or lying position. Neither body position is more effective at working the chest muscles, but the lying position does offer more angle variations, allowing you to emphasize the muscles differently.

  1. Muscles Worked

    • Both the standing and lying fly are effective at isolating and strengthening the chest muscle, or pectoralis major, which consists of two muscle heads. The sternal head is the large, and most visible, chest muscle. The clavicular head is smaller and sits above the sternal head. During the lying or standing fly, the sternal head is the main mover. The clavicular head, biceps muscles and front shoulder muscles are secondary movers. The standing version of the fly exercise activates the stabilizing muscles of the torso, which the lying version does not. These muscles -- the lats, rhomboids and abdominal muscles -- work to hold your torso steady as you move the weights in a standing position.

    Equipment

    • For a lying fly, lie on your back on a weight bench and use either dumbbells or cables for resistance. You cannot use dumbbells for the standing fly exercise, as they do not provide resistance in that plane of motion. You must have access to a cable machine or resistance bands.

    Muscle Emphasis

    • Similar to an incline bench press, an incline fly targets the upper head of the chest muscle, the clavicular head. The decline and flat fly target the sternal head of the chest, with the clavicular head taking a secondary role. During the lying fly, you can adjust a weight bench to an incline, flat or decline angle to change the muscle emphasis. This is difficult to replicate with the standing version of the fly.

    Precautions

    • Both versions of the fly have the same precautions. The fly exercise isolates the chest muscles. The triceps and shoulders are not as involved as they are during the bench press so you cannot use as much resistance for the fly exercise as you can for the bench press exercise. Using excessive weight during the fly exercise increases your risk of shoulder injury. Limit the range of motion of the lowering portion of the exercise. Stop the movement when your elbows are aligned with your torso. Pulling your elbows back behind your torso places the shoulders in excessive extension, which puts undue stress on the chest muscle and the shoulder joint.

    Routine

    • Incorporate both fly variations into your chest routine for variety. Always warm up prior to your workout. Jog, bike or perform an aerobic activity for five to 10 minutes. Do body-weight pushups or light sets of a bench press exercise to warm up the chest muscles. Complete two to three sets of 15 to 20 repetitions before moving on to your working sets of presses and flyes.