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Anatomy and Training the Pectorals


Ever wanted to know how to get a bigger chest? The following is designed to do just that, help you understand how your pectorals really work so you can maximise your training and thus maximise your “pecs”.


The pectoral muscles or the “chest” or “pecs” are made up of the pectoralis major and the pectoralis minor muscles. The pectoralis muscles are fan shaped muscles of the shoulder, with the pectoralis minor lying under the pectoralis major. The two muscles form the bulk of the chest for men and lie under the breasts for women.

In terms of what they do and how best to train them you’ll most likely have heard people referring to the upper, lower and middle pec. These terms are actually more colloquial terms as the pectroalis major only has two sections, it is made up of the two muscle heads; the sternal and clavicular heads. Much of the size and shape of the different areas of our pecs are actually down to genetics and although the overall size of the muscle can be changed, growing specific portions is thought to be more challenging.

To understand how to best train the pecs we first need to understand how they work. The way they help move helps us work out how best to load and therefore affect them for growth.

The Clavicular head is located to the upper region of the chest and is responsible for:

1. Shoulder flexion: Lifting your arm reaching overhead.

2. Horizontal adduction: Lifting your arm reaching overhead.

3. Internal rotation: Lifting your arm reaching overhead.

The Sternal head composes the middle and lower chest region is responsible for:

1. Shoulder extension: Pulling your arm down from an overhead position. eg. a pull-over

2. Horizontal adduction: Pulling your arm across your body. eg. a dumbbell fly

3. Internal rotation: Rotation of the shoulder toward the midline/front of the body


Pec Major vs Pec Minor

The pec major essentially horizontally adducts the arm (moves the arm towards the middle of the body) and internally rotates the shoulder, along with raising and lowering your arm.

The pec minor is an important muscle group for injury prevention more than for performance enhancement or aesthetics. It is responsible for scapular anterior tilt; it pulls the scapulae up and forward on the ribcage. A tight pec minor is a common cause of shoulder pain, especially with issues around the acromioclavicular (AC) joint (the joint at the top of the shoulder).

When training the pecs, most people are looking for muscle growth or hypertrophy (muscle growth) and therefore, maximal activation of the pectoralis major. Despite the separate movement patterns described above, the most effective movement patterns for hypertrophy of the pec major are actually those involving the transverse plane pressing motions. In simple terms, what you’d expect; press-ups, dips, bench press, dumbbell press.

Like training any muscle group, a combination of both isolation (single joint) and compound (multi-joint) exercises are best for muscle growth as they target the muscle from numerous angles, in this case along the sternum and clavicle.

Compound Movements

Compound movements are exercises that involve multiple joints and muscles. An example being bench press and press ups for the chest. To get the very best out of the chest from compound movements variation is key, vary the pressing angle to work the pecs at different angles. Utilise flat presses (bench press, dumbbell press, press-ups and machine press) for a high percentage of the time, but ensure to include inline and decline presses as well.

Don't be afraid of regressions either. People are often too fixated on the bench press and it’s variations. Yes it’s a good exercise, but so is it’s baby cousin the press-up. Despite their similarities, there are some big differences. The bench press is performed by keeping the scapulae (shoulder blades) pinned back and down to give more stability and allow for more weight to be lifted and thus more pec development. However, press-ups force the shoulder blades to move through the active range of motion while the press takes place. The shoulder blades come together during the lower to the ground (retract), and then they actively protract (move away from each other) during the press-up. To perform these correctly think about pushing the body as far away from the floor as possible on the upper part of the movement. This active protraction helps develop the serratus anterior, a muscle group that helps keep the shoulders working correctly.

The press-up is also what’s called a closed chain exercise because the hands are on the floor (and not holding a weight). This is even better for the shoulder as it is great for working the synergist muscles such as the rotator cuff and other stabilising muscles.

Isolation Exercises

Isolation exercises work only one joint and usually involve fewer muscles than compound movements. As always with exercise, one method isn’t the answer, it’s about utilising multiple systems to get the best results. Flys might not be the big compound exercise (bench press is) but they are important for good pec development.


Protocols are different types of training tools that can be mixed up in hundreds of different ways to take your training forward and ensure progression. A whole programme can be based around drop-sets or rest/pause sets with every exercise utilising the protocol. On the other hand, one exercise per session could be subjected to drop-sets and another rest/pause and another trisets. The overarching aim is to take the muscle beyond failure and to make the training more intense. The protocols listed below are great for muscle gain/hypertrophy in general and are perfect for the pecs but equally good for other muscle groups. Work them into your training programme for added chest gains.

Isometric movements are a great type of exercise that people neglect/aren’t aware of. Examples would be holding the barbell of a bench press an inch off the chest or the bottom of a press-up an inch off the floor for as long as possible. Try holding light dumbbells in the lower portion of a fly for up to 90 seconds. A good stretch and a great way to pre-fatigue the muscles.

Drop-sets - Once you’ve tried drop-sets you will love to hate them. Choose a weight you normally lift for 8-12 reps, perform a set to failure in that rep range. Place the weights down and grab a weight 20-30% lighter, any heavier it’s too much, any lighter and it’s too light. Use the new weight to perform as many reps of the same exercise to failure again. Place those weights down and grab another weight 20-30% lighter than the second weight, perform a set to failure again.

Rest/pause sets - Similar to drop-sets in that the idea is to take the muscles beyond failure, but easier to utilise for bodyweight exercises or exercises where multiple weights are a pain (loading and unloading a barbell for example). Perform a normal set of reps to failure with a set weight. Place the weight down and count to 10, pick the weight back up and perform another set of the same exercise to failure. Place the weights down, count to 10 again and then perform a final set to failure with the same weight again.

Compound sets/trisets/giant sets - Essentially stringing two, three or more exercises for the chest together one after another without rest. Try dumbbell press for 8-12 reps into press-ups to failure into dumbbell flyes to failure. Try to do the bigger compound exercises before the small isolation exercises and don't take it easier on the earlier exercises, work hard throughout!


The chest or pectorals is often the favourite of many a trainee looking to add some muscle for the summer. By understanding how your muscles actually work and what they are doing can give you a far better understanding of how to train them. Not only that, you’ll also ensure you add in some press-ups and flys rather than just hammering the bench press as you’ll know it’s not only better for chest development but for healthy injury free shoulders too.