Instructions: Starting position: feet within shoulder’s width distance apart, legs slightly bent. You can start with the dumbbells in front of you or with them at your side. Either one is a good starting position. Imagine a wall running through you from shoulder to shoulder. This is the plane in which you want to keep the dumbbells. If you raise them too far forward you reduce the effectiveness on the lateral deltoid and actually start hitting the front delts.

An analogy: Imagine that you are holding two jugs of water. Blow out as you raise your arms to the side, staying inside the imaginary wall, keeping your arms slightly bent. Gradually turn your arms toward the top of the motion, as if to ‘pour the water out.’ That will give you an additional squeeze, recruiting both the side and rear deltoids.

At the top of the position, if you draw a line from dumbbell to dumbbell, it should go right through your shoulders. Lower the weight slowly while inhaling, bringing your arms back to the original position. Don’t "throw" the weight around. Particularly on this exercise, you want to use slow, deliberate control. You can stretch this muscle by holding each arm straight, pulled against your body with the other hand.