If there was one muscle more responsible than the others for creating a “he must workout” appearance, it’s the deltoids. Not only has broad shoulders been shown to increase attraction from women, but they are also responsible for the illusion of a smaller waistline. On the other hand, failing to train the shoulders appropriately and in a balanced fashion will lead to imbalances that lead to larger imbalances, bad posture due to forced internal rotation of the shoulders, and make you much more prone to shoulder injuries.

Simple Shoulder Anatomy and Functions
Before we jump into the juicy training stuff, let me take a second to go over the simple anatomy of the shoulders. The shoulders aka deltoids are made up of three different heads.

Anterior Deltoid (Front Delt) – Responsible for shoulder flexion as well as internal rotation of the humerus.
Lateral Deltoid (Mid Delt) – Responsible for horizontal abduction.
Posterior Deltoid (Rear Delt) – Responsible for external rotation as well as hyper-extension of the shoulder.

Strengthening the Weak Link
Now let me go over the anatomy of what is easily the most overlooked area of the shoulders when it comes to training. Lack of properly training this area of the shoulders is more than likely the reason that you find it hard to develop bigger shoulders, you get shoulder pain when performing certain exercises, and that it’s hard for you to increase strength in some very important lifts including the bench press.

Rotator Cuff

What are your rotator cuff muscles?

They’re four unique muscles that surround your shoulder capsule. Each one is responsible for a different function and together they help stabilize the glenohumeral (GH) joint.

NOTE: Most shoulder problems can be attributed to a lack of external rotation, overall shoulder mobility, and strength.

Training The Shoulders
Now that we have a basic understanding of the deltoids and their functions, let’s get into the meat and potatoes aka the reason you are reading this article aka how to train for cannonball delts.

Anterior Deltoid – Because the main function of the front delt is shoulder extension, most trainees assume that they must perform isolation exercises like front raises in order to build this portion of the deltoids. What you must understand, however, is that the anterior deltoid is also responsible for internal rotation of the humerus. This simply means that any time we press or push, we are placing a significant load on the front delt. So whether we are performing any variation of bench pressing or any variation overhead pressing, we are loading the front delt. Because it plays such a huge role in these big lifts, it can easily become over developed and imbalanced if we begin to isolate it with things like front raises.

Best Way to Train the Front Delt
If you are training your chest and doing any type of overhead shoulder pressing in your program, then you are not likely to need any other form of direct anterior deltoid work. The load from pressing, whether it be chest or shoulders, is more than enough to stimulate adequate growth in this area of the shoulders and adding in any extra work could be asking for trouble.

Lateral Deltoid – The mid delts are responsible for something called horizontal shoulder abduction. If you’re not sure exactly what that looks like, picture the lateral raise movement. Building this head of the delts is not only the hardest, but the most impactful when it comes to round shoulders. The mid delts are what is going to add width to your frame as well as most of the roundness to the shoulders. Unfortuantly, most trainees either turn the lateral raise into a front delt exercise, or they assume that their overhead pressing movements are sufficient for bringin up with head of the deltoids.

Best Way to Train the Mid Delts
In the video below, I go over 3 tips for performing the proper lateral raise by isolating the mid delt and removing the front delts and traps from the movement completely.

Posterior Deltoid – The rear delts are responsible for shoulder hyper-extension and external rotation but are activated a great deal any time we retract the scapula. In my opinion, when it comes to rear delt training, both compound and isolation movements can be beneficial. You see, the rear delts are trained to a certain degree with most of our back training, however, I do believe that because the role they play in these exercises are small, that one should incorporate some more direct rear delt work in their training for maximum results.

Best Way to Train the Rear Delts
As I mentioned before, the rear delts are activated in most of our direct back training but (in my opinion) not to a significant degree. At the least, I would recommend throwing in some face pulls or cuban presses for a bit more emphasis on the posterior deltoids. I would also recommend a small amount of isolated work from things like rear delt flyes to ensure you are fully strengthening the shoulder as a whole. Isolating the rear delts, however, is not an easy task due to the fact that it can easily become a back dominant movement. For that reason I have included the video below where I go over a few tips you can use in order to fully isolate the target muscle.

Achieve Cannonball Delts
There you have it, the basic anatomy, functions, and training recommendations for injury free, boulder shoulders. Stop the front raises, focus on those mid delts, and never neglect the posterior delts.