Can Inner Chest Workouts Build You The Perfect Chest...

If you're having a hard time building out your inner chest its probably down to two reasons . You're either doing the wrong exercises or you don't understand how the chest muscles works.


This may come as a surprise to you, but there isn't an exercise that isolates the inner chest, simply because the muscle doesn't exist. Its all to do with how the pectoral muscle fibers are constructed and attached to the bone.

This makes more sense when you have a better understanding of the chest's anatomy.

Anatomy of the Chest Muscles

Your chest houses the pectoral major muscle and when flexed there's a visible separation giving the impression of two muscles. Actually, this is an illusion because the pec major is a single mass of muscle but with two different attachments.

As you can see from the diagram the muscle fibers of pectoralis major are attached to the humerus bone (upper arm) then fan out and attach to two different bones, the collar bone and sternum.

The fibers attached to the collar bone is called the clavicular head (upper chest) and the fibers attached to the sternum is the sternocostal head (lower chest).

Areas of the Chest You Can Target

Even though the pecs have have different attachment points you can still target the lower and upper pectorals by using different flye and pressing angles.

For example, decline or flat movements will target the lower chest, whereas incline movements target the upper chest. These are the only areas of the chest you really have any control over.

As pointed out earlier, you can't isolate the inner chest muscle because when a strand of muscle fiber is contracted the entire strand as a whole contracts.

Therefore, so called inner pectoral exercises will engage the middle and outer pecs as well. This doesn't mean you can't build bigger inner pecs. You can, but not in isolation to the rest of the pectoral major.

Don't Just Work The Inner Pecs  

To build an amazing chest you need to use a combination of chest isolation exercises that work both the upper and lower pecs.

For example, to increase upper pecs do exercises with an incline motion as this engages the upper clavicular fibers attached to the collar bone.

In contrast, upper pec exercises are ineffective at working the inner pectoral muscles because they don't engage the muscle fibers attached to the sternum.

To increase the size of your inner chest you need exercises that work that part of the pecs attached to the sternum. So, isolated chest workouts with decline and flat movements are the best options.

But here's the thing. It doesn't matter if its the inner, outer or middle pectoral as they're the same muscle group. The exercises will give you a bigger inner pec only because the lower pectoral muscle as a whole is getting bigger.

Tip: To increase your inner pec mass focus on training the whole chest. In this way, both the upper, lower, inner and outer chest will increase in size in the right proportions.

For this reason, use a complete range of pushing angles, up, down and neutral. In this way, you're working all angles of the pec muscle, upper, lower, inner and outer.

Best Inner Chest Exercises For Gaining Greater Pec Mass

The lower pec muscles have two attachments, the humerus bone (upper arm) and the sternum. Where the sternocostal fibers are attached is the area you want to target as this will add mass and definition to the inner chest area.

In order to engage the inner chest muscle fibers you need exercises that involve a neutral angle/movement. The best pectoral muscle exercises to achieve this is are the flat or decline bench press using a pressing or fly movement.

For an effective lower chest workout I've included two groups of exercises targeting the middle and bottom portion of the lower pectoralis muscles.

Do they isolate the inner chest? No of course not, because as you know, there's no such thing. But they will increase the size of the lower pec and inner chest as well.

Exercises For The Middle Pec

Flat Dumbbell Benchpress

The flat dumbbell bench press is great for targeting the lower pecs because its allows you to fully stretch and contract the chest muscles. In the video above Jay Culter reveals a simple but effective technique to maximize the contractions of the chest muscles.

Tip: Lie flat and arch the back to bring the chest up. As you're pushing the dumbbells upwards you will really feel the burn in the pecs.

Other great tips is to avoid touching the dumbbells together as this engages more of the triceps. Also, don't lock the elbow joints when you extend on the way up.

Flat Bench Dumbbell Flyes

Lie flat on your back. Raise your feet as this helps to stabilize you.

Lower the arms to shoulder level. I see many extend their arms below shoulder level. This is bad form because it puts stress on the rotator cuffs and increases the risk of shoulder injuries. 

Tip: When nearing the top of the movement press the dumbbells upwards so the shoulders move up.

This allows for a greater contraction in the chest when completing the lift.Keep a slight bend in your arms as you lower your arms.Do not extend the arms below shoulder level.

Keep a slight bend in your arms as you lower your arms. Do not extend the arms below shoulder level.

Flat Barbell Bench Press

The barbell bench press is the best known exercise for building bigger chest muscles. Not only does the bench press engage the major pecs it also works many of the muscles of the upper body including the triceps and shoulders.

Tip: By changing the grip you can target different areas of the chest muscles.

For example, the close grip barbell targets more of the inner chest and triceps, whereas a wider grip targets the shoulders and outer chest region. For a more symmetrical and consistent shaped chest alternative between both grips.

Exercises for the Lower Pec

Decline Press

With the decline press the bench is angled downwards by between 20 and 40 degrees. Its a great exercise for adding mass to the lower pec and this has all to do with the decline angle.

The decline creates less activation in the shoulder and anterior deltoid muscles while increasing activation of the pectoral major muscles. Again, correct form is essential to get the most out of this exercise.

When lifting the bar off the pegs, move it over the body so its aligned with the lower chest. Many mistakenly hold the bar above the upper chest area. This means they have to push through the shoulders resulting in more strain on the rotator cuffs.

Another good tip is keep your wrists straight and push upwards as you exhale. Avoid using a false grip, unless you're experienced or have a spotter.

For those who don't know, a false grip is when the thumps are not wrapped around the bar. The grip is more comfortable and enables you to engage more power to lift a heavier load, but the risk of injury is far greater.

Standing Cable Flys

Many trainers recommend the decline dumbbell to work lower pecs however, compared to the standing cable fly it has a distinct disadvantage.

Let me explain. As you raise the dumbbells towards the top the natural force of gravity begins to take over by pulling the weight downwards instead of to the sides.

At this point your pecs are not being worked because the triceps and shoulders are taking the strain to balance the dumbbells above your head.

In contrast, the chest cable fly creates constant tension on your pec muscles through the full range of motion. And because your standing, gravity is no longer a factor so the pec muscles have to keep working to prevent the cables pulling apart.

  • stand directly in the center between the cables
  • do not extend the arms above the shoulders
  • keep feet together and body still
  • the only movement is from the arms squeeze when touching both cable handles together.


The perfect chest shape is rounded with even mass proportions between the upper and lowers pecs with a thin gap down the middle. 

Unfortunately, very few people can attain the perfect symmetrical chest shape. This is not a result of a lack of training. Its simply genetics.

The fact is, chest sizes and shapes will vary from the size of the gap between the pecs, the positioning of the nipples and the roundness of the lower pecs.

Unfortunately, there's not much you can do with genetics, apart from surgery. These surgical procedures are becoming more common among men and often involve inserting fat implants into the uneven gaps. Definitely not for the faint hearted!

Gene Dasci

Hi, My name is Gene and I'm the creator and editor of this website. I've been involved in bodybuilding for over 9 years and my mission is to share my personal knowledge and experience to help you become a better version of yourself.

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