The posterior deltoid, or rear delts, are crucial to stable and healthy shoulders. Under-performing rear delts prevent you from gaining strength with overhead pressing and bench pressing. They also play a crucial role in your posture. Sitting in a hunched position with your shoulders rolled forward lengthens and weakens the rear delts.
Your shoulder muscles, known as the deltoids, are made up of three different muscles: the anterior (front), the middle, and the posterior (rear) deltoid. The latter is one of the most overlooked and under trained muscles in the body.
The King of Rear Deltoid Exercises
The most common rear delt exercise you’ll see is the bent-over rear deltoid raise. HOW TO DO IT: Grab a pair of dumbbells, hinge at your hips, making sure that your back is parallel to the ground, then raise your arms to the side until your arms are parallel to your shoulders.
Tip: You don’t need to go heavy here. Keep weight light to moderate and focus on the muscles you’re moving.
If you don't have access to light dumbbells, another option is the reverse fly machine. During machine reverse flyes, sit down facing the machine, with your palms facing towards each other grab the handles with your hands -- keep a slight bend in your elbows -- and extend the handles until your arms are parallel to your shoulders.
Additional Rear Delt Exercises
The cable cross machine is used for both of these exercises.
1. Face Pulls
Face pulls are the best exercise for building stronger and bigger rear delts. And an excellent exercise for improving posture and overall shoulder health. Our modern jobs require many of us to sit at a desk all day, and that keeps our shoulders internally rotated, creating that “rounded shoulder” posture.
Face pulls help you improve your posture, and when correctly trained, they’ll add more size to your shoulders and help you increase strength.
HOW TO DO THEM: Use a rope attachment and set the pulley machine to just under chin height. Grip the rope from underneath with a neutral, hammer-style grip. Maintain a high chest — pushing your shoulders back — and slightly retract your shoulder blades.
Pull the rope back towards your face, trying to touch the center inside of the rope to your nose. Take a brief pause at the end of the motion and feel the squeeze in your rear delts.
Tip: One way to challenge and isolate your rear delts more is to perform face pulls from a reclined position.
2. Cable Rear Delt Fly
Another great posterior shoulder exercise is the Cable Rear Delt Fly. This machine also doubles as the Chest Fly Machine.
HOW TO DO IT: Adjust the cable of the Chest Fly Machine to a height just above your head; keep your weight selection low. Grab the left pulley with your right hand and the right pulley with your left hand. Cross the cables in front of you to create your starting position.
Move your arms back and outward, while maintaining straight arms throughout your movement. Squeeze your shoulder blades together. Pause for one second, and then slowly return to the starting position.
Training Your Rear Deltoids
You don’t need to go heavy when training your rear delts; a moderate or lower weight is all you need. The ideal rep range for training your rear delts is between eight to 20 reps per set. Perform two to four sets per exercise for optimal rear delt training.
The best days to train your rear delts are on chest or back days. Your rear delts assist in all pulling motions such as pull-ups, cable rows or dumbbell rows. Adding a set or two of bent-over rear delt flyes anytime you train your back muscles will help improve your back strength and posture.
Weak rear delts can also stall your progress on the bench press. As you lower the barbell to your chest, your rear deltoids support your pecs and triceps. But they also aid in helping you push the bar off your chest. So if your rear delts are too weak, you won’t get the bar back up.
For chest day, choose a moderate weight and start with three to four sets of eight to 10 reps of supine face pulls. Later, at the end of your workout perform two to three sets of 12 to 16 reps of machine reverse flyes at a much lighter weight.
Your rear delts support your front and lateral delt on the days you train shoulders. But if you're adding rear delt exercises on your back and chest day, there's no need to additional sets on the days you train shoulders.