The rear deltoids -- known anatomically as the posterior delts -- sit on the back of the shoulders. The best exercises to make these muscles stand out include free weights, such as dumbbells and barbells. Compared to machines, free weights cause you to contract more overall muscle fiber.
The Reverse Fly
The reverse fly targets the rear delts, rhomboids and trapezius, which sit between the shoulder blades. You need a set of dumbbells and either weight bench or workout chair to do these. Sit on the end of the bench with your feet together and weights held at your sides with your palms facing each other. Slowly bend forward and let your arms hang down at your sides. Keeping your arms straight, raise the weights up to your sides until your arms parallel the floor. Hold for a second, then slowly lower the weights and repeat.
Barbell Rear Delt Raise
The barbell rear delt raise works the posterior delts, biceps and upper trapezius. Before you begin, place a barbell on a squat rack and stand with your back to it. Carefully grasp the bar with an overhand, shoulder-width grip and lift it off the rack. Your arms should be straight at your sides at this point and your palms should be facing backward. Steadily lift the bar up as high as possible by bending your elbows. Hold for a second, slowly lower the bar and repeat. As you raise the bar, keep it as close to your body as possible.
Barbell Rear Delt Row
A barbell rear delt row is performed with the bar in front of your body. Before you start the exercise, add weight to the bar, place it on the floor and stand behind it with your feet about shoulder-width apart. Bend down and grasp the bar with a wide, overhand grip and lift it off the floor. Keeping your back slightly higher than parallel to the floor and knees slightly bent, pull the bar up toward your body. Try to get the bar to touch your upper chest lightly. As you do this, squeeze your shoulder blades together and hold for a second. Slowly lower the bar down until your arms are fully extended and repeat.
Inverted Row
An inverted row works the rear delts with the weight of the body. You need a Smith machine to do this exercise. A Smith machine has a barbell that slides up and down and can be locked into different positions. Lock the bar at about waist height, lie underneath the bar and place your hands on it with a wide, overhand grip. Keeping a straight line from your heels to your shoulders, pull yourself up until your upper chest is close to the bar. Hold for a second, slowly lower yourself down until your arms are fully extended and repeat. When you pull yourself up, make sure to squeeze your shoulder blades together.
