Muscle Study: The Pectoral Muscle

In each muscle study, we’ll take a look at a muscle group, and examine what its purpose is in the body. Then using that information, we’ll take a look at a few ways to exercise the muscle and close with a sample workout that should effectively work the muscle. We’ll dive a little deep on this one, with a lot of technical jargon, but I’ll do my best to explain in plain English the biological terminology we’re throwing around as we go along!

The pectoral muscle (or pecs as they’re often referred to) are the muscles that connect the anterior (front) of the chest to the upper arm and shoulder. It consists of 1 major and 3 minor muscles:

  • The Pectoralis Major
  • The Pectoralis Minor
  • The Serratus Anterior
  • The Subclavius

The Pectoralis Major

This is the largest and most visible muscle in the pectoral grouping. It attaches to the body along the sternum and clavical on one side (the center of your chest and the collar bone), and the intertubercular sulcus of the humerus (A groove in the bone near the top of your arm). It adducts and medially rotates the upper arm – a fancy way of saying it pulls your upper arm toward the center of your chest while rotating it the same direction.

Because this muscle is so large, it is subdivided into three parts:

  • The Clavicular Part
    This is the topmost portion of the Pec Major that connects to the clavicle
  • The Sternocostal Part
    This part of the muscle attaches to the anterior sternum and makes up the bulk of the Pec Major
  • The Abdominal Part
    The underside of the pec major that connects near the top of the abdominal muscles

The Pectoralis Minor

This is a smaller muscle that lies underneath the pectoralis major. It connects to the third, fourth and fifth ribs (counting from the top of the chest down, just under the collarbone) and the coracoid process of the scapula (a small hook-like structure on the side edge of the inside top portion of the shoulder blade). It helps to stabilize the shoulder blade by pulling it toward the rib cage.

The Serratus Anterior

Another smaller muscle in the group, the serratus anterior is located toward the side of the chest wall forming a midline border under the arm. This muscle is made of several strips connecting the first 8 ribs on one end, and the rib facing surface of the midline border of the scapula (shoulder blade). It’s an important muscle that rotates the scapula allowing you to raise your arm past 90 degrees and also help hold the scapula against the rib cage.

The Subclavius

This is a small muscle located beneath the collarbone. it runs horizontally almost parallel to the collarbone, but connecting it to the first rib. Its function is to hold the collarbone in place.

So What Do These Muscles Do In A More General Sense?

According to the Trifocus Fitness academy:

“The chest muscles are predominantly used to move and control the arm by pulling on the humerus to perform vertical, lateral and rotational movements… The pec muscle is also involved in moving the rib cage during deep breathing.”


  • A strong chest can help to improve your posture
  • Improve your ability to push things
  • Improve swinging movements (like swinging a golf club or tennis racket)

So How Do We Best Work These Muscles?

Since the primary movement that the pectoral muscles serve is adduction of the upper arm (pulling the upper arm closer to the centerline of the body), this tells us that when we perform an exercise to strengthen this muscle, we should be focusing on squeezing the muscle when it’s moving the top of the arm closer to this mid line – or at least in that general direction.

If you stop and think about the movements that best accomplish this goal, you’re left with pressing movements where the shoulders are behind the plane of the chest and are moved forward (like the bench press) or where the arm is to the side of the body and it moves forward in an arc to squeeze the pec and bring the top of the arm closer to the mid line of the body (like a chest fly movement).

Bear in mind, these are only the MOVEMENTS to best work the muscle. There are numerous ways to perform the movements themselves. You can using barbells, dumbbells, cable machines, TRX Bands, Resistance Bands or just your body and gravity in the case of a push up. Altering the angle of a bench from flat to inclined or declined, the height of the pulleys on a cable machine or even just a couple of books under your toes or varying the distance between your hands during a pushup will alter which part of the muscle is being used.

With that out of the way, let’s get into the details of these movements and try to figure out the most effective ways to perform each one for the best results.

The 3-Step Bench Press And Push Up

I’m combining the bench press and push up together because the movements are very similar in how they’re performed. However one requires some equipment and one does not, but the basic set up for each is the same. For a bench press, you will (obviously) need a flat weight bench to lie back on. Your feet should be flat on the floor, and you should focus on keeping your lower back close to the bench by contracting your abdominal muscles during the exercise.

1To start either the bench press or push up, begin with the arms extended, slightly more than shoulder width apart. Your shoulders should be back and down, shoulder blades slightly pinched together.

2In the case of a bench press, lower the bar slowly over a mental 3 or 4 count until it touches your chest. In the case of a push up, lower your body toward the ground stopping about an inch from touching. Your core should be tight in either exercise, and the shoulders should remain held back, with the focus on leading with your chest (not your shoulders). At the end of the movement, you should squeeze your pectoralis major for a mental count of 1.

3Return the bar back to the starting position, or your body back to the raised position, arms fully extended during a mental 1 or 2 count and repeat the movement until failure (the point at which you cannot perform another movement, or you cannot perform another movement without sacrificing form).

Notice the counts that I’ve given. These are not fast movements, a lot of times in the gym, you’ll see people very quickly performing movements. You’re smarter than that. Speed does 2 things, 1) it encourages sloppy form, which can lead to injuries and 2) it may make the movements easier as the muscle has less time to fatigue, but it also makes them less effective – and that’s not why you’re doing them. Performing the movements slowly, with an emphasis on the eccentric (the lengthening of the muscle as it develops tension and contracts to control the motion) will make the exercise more difficult, but that’s what’s going to maximize your results.

To focus on different areas of the pectoralis major, the bench can be raised or lowered. When the bench is flat, the exercise will stress the sternocostal (horizontal middle) of the pec major. When inclined to around 30 degrees, the bench press will work the clavicular and upper portions of the pec major – too steep and this will work the front of the shoulder, so don’t go too extreme. When declined, an angle of 15 – 30 degrees is sufficient to target the abdominal part – or underside of the pec major. The same angles can be used for a push up to target different areas of the chest. You can accomplish an incline or decline in a pushup by utilizing the first or second step on a staircase, or an aerobic step under either the hands or feet to simulate the angles outlined.

By changing the position of the hands in a push up, or bench press, the outer to center of the chest can be targeted. This is fairly intuitive, the further in or out the hands are, the more stress is placed on the corresponding part of the pec major. Pushups have a benefit for the innermost chest as the hands can be placed extremely close together in a “diamond” position to really target the center “cleavage” of the chest.

The 3-Step Dumbbell Fly

The set up for the dumbbell fly is very similar to the bench press with regard to the bench and positioning of the feet and use of the core muscles to stabilize the body. Start with light weights if this is your first time doing this exercise, and be aware of any pain in the shoulder. This movement can place a lot of strain on the shoulder joint – even with light weights, so be careful! Better still, perform this exercise lying on the floor or another surface that will give additional support to the shoulder to help prevent injury.

1Similar to the bench press, to start a dumbbell fly, begin with the arms extended, slightly more than shoulder width apart. Your shoulders should be back and down, and shoulder blades slightly pinched together. You should also include and maintain a slight bend at the elbow throughout the entire movement.

2Lower the the weights slowly to either side of the body over a mental 3 or 4 count until your hands are a few inches above the same plane as your shoulders, with your palms facing upward. At this point, your elbows should be just slightly behind the plane of your shoulders (or touching the ground if performing this exercise with additional shoulder support) and you should feel a stretch across the front of your chest. Your core should be tight, and the shoulders should remain held back.

3Return back to the starting position. On the way back up, you should focus on squeezing your pec major and allow that squeeze to be the leading force returning your arms back to the starting position over a mental 1 or 2 count and repeat the movement until failure (the point at which you cannot perform another movement, or you cannot perform another movement without sacrificing form).

The bench press and chest flys, can both be performed to great effect standing with a cable machine as well if preferred, but the strength needed for core stabilization will likely limit the amount of weight you will be able to use. This is a great way to add variety to your chest workouts and stimulate the muscle differently than your body is used to in order to push through plateaus. The angles can easily be changed by raising or lowering the pulleys from inline with your shoulders to either slightly above or below them to simulate an inclined or declined position.

Putting It All Together

Combining several of these exercises together will allow you to create a chest focused day in the gym that will help ensure that you’re fatiguing the entire muscle group and balancing the effect of your work on the pecs. An example of a well rounded chest routine might be:

Depending on your goals – size or definition, you should focus on heavier or lighter weights respectively and increase or decrease the repetitions to ensure full fatigue.

Your pec workouts don’t need to be exhaustively long, they just need variety to work each area of the chest and they should fully fatigue the muscle by the end of the workout. By combining a short chest routine – like the one above – with another muscle group, like the biceps or triceps, you can create an effective workout that wont leaver you spending hours in the gym!

Stretch That Thing!

Strengthening the muscle isn’t good enough. With all muscle groups, if the muscle is tight, it can lead to other problems. A tight chest can lead to slouched shoulders and poor posture (which can lead to many other issues). Any time you work a muscle, you should also stretch the muscle. A few stretches you could perform after a chest workout might be:

Wrap Up

There are many reasons to exercise this muscle group, ranging from functionality to simply aesthetic reasons. Hopefully this article sheds some light on the complexity of this popular muscle group, and increases your knowledge of how it’s used by your body. I’d love to hear your thoughts on ideas how you might be able to train it to work even harder for you.

Know someone who might like this article? Please share it with them, or via your social media network, it helps the blog out, and you never know who you might be responsible for motivating to live a healthier lifestyle!


Teach Me Anatomy

Ken Hub

Why Pectoral Strength Is Necessary

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