Muscles worked: Pectoralis major (upper chest), Anterior deltoids, Pectoralis minorStarting Position:1. Lie on your back on a 45 degree bench with your feet flat on the floor. If you have an excessive arch in your back, place your feet on a step so that your knees are bent at 90°.2. Hold a PowerBlock (or Dumbbell) in each hand and hold them above your chest with your arms extended and palms facing each other. Bend your arms very slightly.The Movement:1. Slowly lower the PowerBlock (or Dumbbell) out to your sides in a semi-circular arc. Keep your elbows locked in the slightly bent position throughout the range of motion.2. When your upper arms reach shoulder level and you feel a strong stretch in your shoulders, return the PowerBlocks (or Dumbbells) to the starting position, following the same arc. Do not pause at the bottom of the movement.Tips:• Maintain the slight bend in your elbows. Don't allow them to bend to 90° otherwise this turns the movement into a PowerBlock (or Dumbbell) press.• Do not allow your upper arms to go much below shoulder level as this could place excessive stress on the shoulder joints and risk muscle or tendon tears.Variations:Incline fly: Performing flys on an incline bench set at 30-45° increases the stress placed on the upper chest and anterior deltoids. It is therefore particularly good for developing mass and thickness in the upper chest.