Update:
This article was total nonsense. Incline exercises absolutely do emphasize the upper chest. Though all fibers do contract at their endpoints, they differ in tension according to internal moment arms within a muscle, with sarcomere non-uniformity and other effects such as stretch and probably cell swelling leading to non-uniform growth.
Many trainees approach bodybuilding like a sculptor. They choose exercises to build muscle in precise areas, like pressing and molding clay to form the contours of a statue. They may aim to achieve an ideal proportion, believing they have total control over their development.
This analogy fails though when you come to understand the anatomy involved. Muscles act at their origins and insertions. These endpoints attach the muscles to the tendons, allowing them to act upon bones. When a muscle contracts, it simply acts at all of its endpoints. Imagine pulling hard on each end of a rope. Could any degree of finesse allow you to emphasize certain strands?
This concept applies to the chest as well but alone does not reveal the whole truth. If an endpoint covers a broad region then specific muscle fibers may preferentially activate depending on the joint angles. The chest, with the lower sternal portion and upper clavicular portion, functions as such an example.
As long as you push horizontally with a heavy weight though, the entire chest contributes intensely to the movement. This choice also keeps your shoulders and other joints safe. The other involved muscles work evenly along with contracting close to their ideal lengths. This optimizes strength and size gains by maximizing tension.
Consider these reasons to build the upper chest with the flat barbell bench press alone.
Reasons
Nothing in biology makes sense except in the light of evolution.
– Theodosius Dobzhansky
- The upper and lower chest diverge only for lesser functions.
The pectoralis major has two portions, the sternal or lower large portion and the clavicular or upper small portion.
The sternal head assists with adduction of the shoulder, such as when pulling on the row. The clavicular head assists with shoulder flexion, which occurs with an overhead press, requiring an action that evolved to take place only as an unloaded or very light movement used for repositioning.
Both serve as lesser functions that fail to address each part adequately. Otherwise, they come together for transverse or horizontal shoulder abduction, which occurs on a flat bench press. This form of push serves as the safest and strongest function for each.
As a general rule, any time a group of muscles come together for an important and naturally-occurring purpose, such as when needed to lift something heavy or to move fast, you will observe the true way that the body prefers to handle such a situation. The bench press would allow the most strength and speed to be applied by these muscles. A push at a steep angle would never come about in such a scenario, at least when given a choice, as the muscles would function weakly.
- Incline presses and flyes of any kind harm the shoulders.
Using awkward exercises and angles to hit different parts of the chest will harm your joints. These exercises cause shoulder impingement. This creates damage that you can prevent by merely avoiding them.
Flyes in particular apply a long moment arm where the chest functions at a weak and stretched length. They encourage too much range of motion and possess all of the negative properties associated with isolation, such as placing shear forces on the shoulders.
Avoid reducing the weight and performing more reps to counter this effect. The limitation and injury will just occur over time instead of suddenly. The improvement for the chest will lessen in either case.
The flat bench press presents a suitable angle for the upper chest to recruit fully and also allows enough effort and weight. If still unsure, you will notice that the upper chest gets sore if you do too much work on the flat bench press. This would not happen if this region failed to activate.
- Effort and load recruits fast-twitch muscle fibers.
You need a minimum amount of effort and weight to recruit the fast-twitch muscle fibers.
Motor unit recruitment dictates that the fast-twitch muscle fibers join the fray exclusively for heavy or fast actions. The slow-twitch muscle fibers perform nearly all of the work for easier, repetitive movements. This is relative though. A weight that feels heavy through exhaustion, without too long of a time under tension that brings different types of fatigue, and demanding the intention to move fast, despite the weight travelling slow, will recruit the fibers most responsible for size and strength.
Poor exercises reduce the effort and weight possible since these actions go against your anatomy. Using incline presses, flyes, and machines place uneven and harmful forces on the joints and work the muscles at weak lengths. Any slight emphasis to benefit the upper chest, in theory, goes away when you consider this reality. Limiting the weight possible by avoiding a muscle’s strongest action will always reduce strength and size gains.
When you work your chest, you either work the fibers at a weaker or stronger length throughout the range of motion. Your muscles work best near or at the midpoint for a good exercise. The sites within the muscles responsible for contraction form more connections due to an optimal overlap. This allows more tension, the main stimulus for size and strength.
This midpoint occurs with your elbow lined up or just slightly behind the plane of your shoulder for the chest. As you start to move away from this, the components overcrowd or move too far apart. Only the flat bench press allows a medium position when considering all of the joint angles.
Strong and safe joints also tolerate the intensities needed for growth. It prevents the nervous system from stymieing effort. This can happen when it anticipates problems.
Medium stances and grips recruit all muscles uniformly and distribute the load across all the joints. Choosing the flat bench press with a standard grip, neither too wide nor too narrow, will also allow the other involved muscles to develop tension. I suggest using a barbell as well to maximize the stability needed for expressing your fullest strength.
- Genetics determines muscle shape.
Consider the biceps.
Many bodybuilders perform endless variations of curls to develop all its parts. They determine these parts through feel and without a consideration for anatomy. They perform preacher curls to address the lower biceps. They perform concentration curls to develop the peak. They perform incline curls to develop the belly.
These curl variations only change the length of the biceps by adjusting the positions of the elbow and shoulder. This just overloads the same fibers at various weak lengths by altering leverage. A weak length of the biceps forces the brachialis, which attaches to the elbow, to compensate along with the brachioradialis. These develop the illusion of emphasis, which also comes from the elbow stress due to higher stabilizing and destabilizing forces.
They could achieve the best growth instead by using an underhand dumbbell row. This works the biceps at its strongest length. It protects the elbow and addresses many other muscles optimally as well.
Muscle appearance comes from your genes and not through an unbalanced exercise selection. Adding size reveals this appearance. As a fan-like muscle, exercises may promote slight differences in activation for each part of the chest but only when used with very light weights irrelevant to strength training. Once you go heavy enough to trigger size and strength improvement on the right exercise, every fiber that can play a role will.
Notice that those with big upper chests have big overall chests. Add muscle and the upper chest will grow. Those with weak upper chests will always possess relatively weak upper chests. The present ratio always determines the future ratio.
When a skilled bodybuilder strikes a side chest pose correctly, he or she can emphasize the upper chest. This makes it appear larger by compressing the pecs together. Bodybuilders use this and other tricks to make it seem as if specific training morphed their upper chest. This only misleads trainees.
Perhaps mysteriously, consider that the indirect effect may even prevent drastically uneven growth for an individual.
Build the Upper Chest with the Flat Bench Press
You will certainly find the upper and lower difference for the chest legitimate, but emphasizing each part through different exercises is misguided.
The flat barbell bench press ranks as the safest option. Use this to continually overload the upper chest. Use more weight, in good form, as you grow stronger.
Stick with the pushing motion the body developed to activate the whole chest effectively. Grow the upper chest the same as for the lower chest. Build the upper chest with only the bench press.