Inner Chest Workouts for Perfect Pec Definition

The inner chest can be notoriously difficult for bodybuilders to develop because many of the exercises their using are only targeting the lower or outer areas of the pecs. In this article we're going to look at 6 inner chest workouts guaranteed to develop the whole chest.


Building bigger inner pec muscles is not as straightforward as training your biceps or triceps.

The chests anatomy is a little more complicated than that.

Even so, building bigger pecs isn’t rocket science either. There is a systematic scientific approach to get the results you want.

Unfortunately, most guys never make progress and its usually because of these three problems...

  • 1
    They don’t understand the chests anatomy
  • 2
    They're doing the wrong exercises
  • 3
    They're doing the correct exercises with the wrong form and technique

BTW, problems two and three are symptoms of problem one – not understanding the chests anatomy and its relation to the various angles of upper arm movements that affect it.

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.

Chest Anatomy 101

Your chest consists of two separate muscles.

  • 1
    The pectoralis major 
  • 2
    The pectoralis minor 

But, it's the pectoralis major that you need to focus on. 

The pec major is divided into three sub-sections or heads:

  • 1
    Clavicular Head (upper chest)
  • 2
    Sternal Head (lower chest)
  • 3
    Abdominal head

Each sub-section relates to the attachment points of the muscle fibers.

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.

With the clavicular head the muscle fibers are attached along the clavicular or collar bone and run at an angle to the humerus (upper arm) bone. This area is the upper chest.

Muscle fibers attached to the upper arm and chest bone (sternum) is the sternal head. This forms the largest part of the chest and is better known as the lower chest area.

The function of the sternal head (lower chest) is to move the arms across the body.

The abdominal head is a small band of muscle fibers that run from the humerus along the lower chest and attach themselves to the upper abdominal muscles.

The two main functions of the chest is to push the arm away from the body and to bring the arm across the chest.

This movement across the chest is known as an adduction/lateral motion.

As you can see from the diagram it's the sternal head (lower chest) you need to isolate and target if you want to grow your inner chest. 

Can You Target The Inner Pec

There aren't any exercises that specifically target the inner pec because the fibers attached to the sternal head form part of the whole lower pectoral muscle.

So, when a strand of muscle fiber is contracted the entire strand as a whole contracts.

Which means you can't make your inner pec bigger or stronger without making the whole lower chest bigger and stronger.

The only way to make the inner chest bigger is to make the whole chest bigger.

That's why, 'so called' inner pectoral exercises will also engage the middle and outer pecs.

But, this doesn't mean you can't build bigger inner pecs.

Peak Activation Explodes your Inner Chest 

For better results you've got to use inner pectoral workouts that fully contract the muscle fibers attached to the sternum.

But you also need to shut out muscles that don't contribute to the development of the inner chest.

Here's the deal.

Complete chest muscle contraction causes peak activation and recruitment of muscle fibers, and its this, that will make your inner pecs pop.

Lateral Resistance to Expose the Inner Chest Line

Because there are different attachment points resistance has to be applied at different angles in-order to engage the upper and lower pectoral muscles. 

And the best workouts for inner chest activation are fly and pressing exercises.

For example, decline or flat movements target the lower chest, whereas incline movements target the upper chest.

Most recommended workouts are ineffective at building inner pecs

When it comes to building a bigger chest, press-ups and bench presses are often recommended.

The fact is, they're not the most effective exercises for building an eye popping inner chest line. 


Because vertical pressing movements don't give you a full contraction of the lower chest muscle.

To target the inner pecs you need to bring your arms across the chest because this lateral or horizontal adduction movement maximizes recruitment of the chest muscle fibers. 

Adduction is the movement of a body part toward the body's mid-line. So, if a person has their arms straight out at the shoulders and brings them down to their sides, that's an adduction. 

So, what you need are exercises that provide a maximum range of motion to fully activate muscle fibers attached to the sternal head. 

Tension is Key 

Muscles can't determine how heavy the weight is you're lifting. 

The only force muscles respond to is torque or tension.

 Lifting heavier isn't going to make your chest bigger but, increasing the amount of tension will.

That's why the best coaches teach professional bodybuilders special techniques enabling them to lift half the weight while keeping the same amount tension on the working muscle.

By applying tension with intent you selectively fatigue the target muscle without damaging your joints and ligaments in the process.

 It amazes me how few people do this because these muscle gaining techniques are actually simple to do 

For example, with the barbell bench press time under tension decreases as you're pushing the bar upwards. 

By the time the arm is fully extended there’s little to no tension being applied on the pecs. That's not efficient at all.

But there's a special technique you can apply to ensure you’re applying tension throughout the range of motion.

To find out more... click here

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.


Increase your inner pec by training the whole chest. In this way, both the upper, lower, inner and outer chest will increase in size in the right proportions.

Best Workouts for Inner Chest Development

Inner Chest Push Up

This is a simple but effective push up to develop your inner pecs.

Its as simple as positioning your hands closer together. In this way, you still recruit the tricep muscles but it also creates tension on the inner chest. 

Also, its important to mentally focus on the muscles you're contracting.

Take the usual press up position and instead of the usual shoulder wide arm position go a little narrow by placing your hands closer together.

Next, contract your pecs and focus on that contraction as you perform the inner chest press up.

As you come up really pinch or contract the pecs. That little contraction is going to help you get that inner line cut between the pecs.

Its a great exercise you can perform at home, in a hotel room, or in park. 

Here's a video demo that shows you how to do it...

Flat Dumbell Press

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.


Lie flat and arch the back to bring the chest up. As you're pushing the dumbbells upwards you'll start to feel your pecs burning.

Another great tip is 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.


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 the arms as you lower them. 

Don't 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 muscles of the upper body including your triceps and shoulders.


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 between 20 and 40 degrees.

Its this decline angle that makes it a great exercise for adding mass to your lower pec's.

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.

Don't make the mistake of holding the bar/dumbbells above the upper chest as this causes you 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 but, compared to the standing cable fly it has a distinct disadvantage.

Here's why.

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. Your pec muscles have to keep working to prevent the cables pulling apart.

Here's how you do it...

  • stand directly in the center between the cables
  • don't extend the arms above the shoulders
  • keep feet together and body still

Remember... the only movement is the arms. Squeeze those pecs 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!

Maximizing Chest Development

When performed consistently, the inner pec workouts above, are going to give you that clear line down the middle of your chest.

And when you apply science and correct form to your inner peck workouts bigger and faster results are guaranteed, which is very motivating.Look.

If you're interested in a complete training that shows you step by step how to grow a bigger pair of pecs with eye-catching definition, click here now.

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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