Shoulder Muscle Anatomy & Training Guide

“I ask not for a lighter burden, but for broader shoulders.”

Your shoulder muscles can make for a striking appearance. Wide shoulders are eye-catching symbols of health and strength and an important part of creating a V-shaped torso.

Athletically, your shoulders are the foundation for every action your arms take. Whether you’re pushing or pulling, or even lifting something with your arms by your sides, your shoulders take the brunt of the work.

On this page, you will find an introduction to shoulder muscle anatomy, links to the best shoulder exercises, and all our shoulder workouts and resources.

Shoulder Muscle Anatomy

Your shoulder muscles, or deltoids, consist of three distinct sets of muscle fibers: the anterior deltoid, lateral deltoid, and posterior deltoid. Or, in simpler terms: the front delts, side delts, and rear delts.

Deltoid shoulder muscle anatomy
The three sets of muscle fibers in the deltoid muscle. Front deltoids in red, side deltoids in green, and rear deltoids in blue. © The Database Center for Life Science.
  • Your front delt originates from the outer part of your clavicle, next to the clavicular part of your pectoralis major. It inserts in the front of your upper arm bone (humerus). The primary function of your front delt is to bring your arm forward (flexion), such as in pressing movements or front raises.
  • Your side delt originates from your acromion – the bony process of your shoulder blade that forms the “roof” of your shoulder joint – and insert into the outside of your upper arm bone. The primary function of your lateral deltoid is to lift your arm out to your side (abduct), like in a lateral raise. It is also essential for keeping your shoulder joint in place when you are carrying or lifting things.
  • Your rear delt originates from the back of your shoulder blade, partially covering your rotator cuff. It inserts on the outside of your upper arm, and its primary function is to bring your arm back (extend) and externally rotate it. It is a synergist to your lats in shoulder extension and a synergist to infraspinatus and teres minor in external shoulder rotation.

These are not separate segments but rather a continuous arrangement of muscle fibers that all converge into the same tendon, inserting on the outside of your upper arm bone.

Other groups of muscles that cross your shoulder joint are your chest, lats, and rotator cuff. Your trapezius muscle doesn’t cross your shoulder joint but attaches to your shoulder blade, which makes up the base of your shoulder joint.

Anterior (front) muscles of your shoulder.
Back of shoulder muscles anatomy
Posterior (rear) muscles of your shoulder.

For complete shoulder training, you should perform exercises that bring your arm …

  • Forward (flexes your shoulder)
  • Out to your side (abducts your shoulder)
  • Backward (extends your shoulder)

If you perform exercises that involve each of these three movements, you will have trained all of your shoulder muscle fibers.

Shoulder Exercises

Which are the best shoulder exercises?

The answer to that question will depend on your goals and current fitness level, among many other factors.

Still, below are some of the best shoulder exercises many individuals can perform to build bigger, stronger shoulder muscles.

Note that these exercises will target different heads of your deltoid, and you will need to combine several of them for total shoulder development. Every exercise also has several possible substitutes that can work equally well, or even better, depending on your circumstances.

Top 10 Best Shoulder Exercises

  1. Overhead Press
  2. Push Press
  3. Seated Dumbbell Shoulder Press
  4. Barbell Front Raise
  5. Dumbbell Lateral Raise
  6. Behind the Neck Press
  7. Barbell Upright Row
  8. Reverse Dumbbell Fly
  9. Face Pull
  10. Barbell Rear Delt Row

For a detailed explanation of which deltoid heads each exercise works, why we recommend it, and possible substitutes, please refer to our guide on the best shoulder exercises:

The 10 Best Shoulder Exercises for Muscle & Strength

Shoulder Workouts

Over the years, we have produced a number of shoulder workouts for different goals and purposes.

Below are some of our most popular shoulder workouts routines:

  • StrengthLog’s Shoulder Workout. This is a basic but comprehensive shoulder workout for muscle and strength gain. With five simple exercises, you will work all parts of your deltoids and increase your upper body strength.
  • Dumbbell Shoulder Workout at Home. A complete dumbbell shoulder workout for building delt size and strength in the comfort of your home.
  • Chest & Shoulder Workout. This a hypertrophy-focused workout for intermediate to advanced bodybuilders or experienced lifters who want to give bodybuilding a go. You will combine heavy pyramid training with moderate-load isolation work for a good pump and growth.
  • Back & Shoulder Workout. Similar to the above, this is a bodybuilding-style workout to maximize muscle growth in your shoulders and back. High volume, plenty of exercises, and a medium rep range.
  • Shoulders & Abs Workout. The final high-volume bodybuilding-style shoulder workout of the litter. In this workout, you combine shoulder training with ab training.

All of these workouts are available in our workout app, which you can download for free with the buttons below.

Download StrengthLog Workout Log on App Store
Download StrengthLog Workout Log on Google Play Store

Shoulder Training Programs

These are training programs for increasing your overhead press strength.

  • Press Pasodoble. 3x/week. A six-week upper body program focusing on increasing your overhead press strength and giving you boulders for shoulders.
  • Russian Pressing Ladder. 3x/week. A five-week program for improving your overhead pressing strength. Originally intended for the kettlebell press, but works just as fine for the barbell overhead press or the bench press.

Of course, shoulder training is included in most of our other training programs. If you are primarily interested in muscle hypertrophy, I recommend you check out our bodybuilding programs.

Alternatively, take a look at our full list of training programs.

All of our training programs are also available in our app, which you can download for free with the buttons below.

Download StrengthLog Workout Log on App Store
Download StrengthLog Workout Log on Google Play Store