The chest muscles or the “pecs” as they are known are one of the most coveted muscles in the man, and is also one of the most desired muscles that the other sex looks for in a man.
I mean show me a woman who doesn’t like a big chest!!
I am going talking you through the science bit specifically the function of the muscle and how to fully shorten and lengthen it as I want you guys to be smart and be different than the majority of guys in the gym.
Once you know the function of a particular muscle and how to fully lengthen and shorten them you will start to understand why we do an exercise and your form will become better.
Once you tighten up your form you will be in a position to build bigger muscles faster
The Science bit
The pectoralis major as it is known is a thick, fan shaped muscle that is situated at the front of the human body (the chest) and makes up most of the muscles in the chest.
This muscle attaches from the sternum and runs all the way to the clavicle, ribs and parts of the humerus.
The main function of the pecs is to move the shoulder joint.
Specifically, flex the humerus (shoulder) or in simple terms bringing the arm up, adducts (bring in toward the centre of the body) and internally rotates the arm (bringing it towards the body).
The Pecs comprises of 57-68% fast twitch muscle fibers (Type IIa, Type IIb). As we have said before your type II muscle fibers have a higher potential to grow, than their type I fibers.
However I am not saying that you should not do any work for the type I fibers but the majority of your work should be to work the type II fibers.
Range of motion
This is a grey area and one where so much confusion arises. What is an optimal range of motion? Should you or should you not be touching your chest?
There is no easy answer that I can give you. The answer is not as simple as a yes or no.
It is all about minimising the risk and enhancing the benefit. You will hear spotters telling the guy on bench press “touch your chest”, well that’s not exactly correct and I will explain why.
Each exercise has its own range of motion and each individual has their own range of motion.
You ask how?
Well it is all to do with your structure or genetics as we know it. You might see some people with bigger body parts than others, big triceps and back but lagging chest as examples.
All that means is that your body is mechanically stronger in these departments so it uses these muscles more during heavy lifting.
Of course correct lifting techniques has a lot to do with it, believe me I can show you how to recruit your Rhomboids and Rear Delt muscles during a bench press instead of your chest!
The range of motion that is often taught for the chest is to bring the arms down to parallel or 90 degrees.
But this is where it gets confusing. Parallel or 90 degrees for you and me are entirely different.
Some guys have short arms, some have long limbs and narrow ribcages. All these factors and more affect the range of motion for an individual.
Doing an exercise is not as simple as watching someone do it. Nothing can beat a trained eye in spotting the techniques.
You can get an idea of your available range of motion of the antagonist muscle (the opposing) in the case of the chest it is pulling backwards (external rotation) so that would be the muscles on the back.
Hold a broomstick and bring it towards your chest mimicking the bench press, where the broomstick ends up relative to your chest will be your approximate range of motion for your chest.
If you find your range of motion is a lot less than what you have been following before the chances are that you will find that your pecs are able to do a lot more work than before as you are now using the muscles that you are supposed to be using.
On a side note if you are lacking rib cage depth you will need to emphasise your scapular retraction (shoulder blades) more than a person who has a good depth in order to get a better pull on your pecs.
It is critical that you are aware of what your scapula is doing when you are doing a chest exercise as this influences muscular contribution in the chest.
I would say that I have a good chest development but for some unknown reason I developed bad habits in my lifting techniques, whereby I was going past the 90 degrees which put too much stress on the rotator cuff and ended up not using the chest muscles properly during the exercises.
You can correct this but it takes time for your brain to learn new movements
As we talked about above your shoulder positioning can alter the way your chest muscles work.
The pecs are best worked in a transverse plane with shoulders abducted at 90 degrees with elbows in line with shoulders.
Fully lengthened or shortened muscle
One of the key ways to optimally build muscle is to fully lengthen and shorten a particular muscle.
In a lot of cases this involves lengthening the antagonist muscle in order to shorten the muscle that you are trying to work.
Think of the bicep, in order to fully lengthen it you need to shorten (contract) the triceps.
When the biceps are shortened (contracted) the triceps have to relax (lengthen).
So to a fully lengthened chest goes like this, externally rotated humerus, arms fully extended behind you and palms down.
NOTE: Retract your scapula (shoulder blades at the back) and NOT your elbows as you will strain your shoulders that way.
That means the muscles on your back are contracted.
So how do we fully shorten or contract the pecs?
As we said before the function of the pecs is to rotate the humerus and adduct the arms. So the arms have to come across the body and elbows locked out.
Where you grip the bar and the dumbbells have a great bearing on where you will recruit the muscles.
Ideal grip position for the bar is just outside shoulder width. Your elbows should be perpendicular with the ground at the bottom of the rep. If your hand position is outside that you will use less chest and more biceps, go too narrow and you will use more triceps and less chest.
A common mistake that I see often is incorrect breathing techniques. Far too often I see guys not taking a deep enough breath or letting the air out far too quickly at the beginning of the lift.
Why is this wrong?
Well it results in the decrease of the angle of the pull on the chest because it reduces the depth of the ribcage.
As far as selecting the right exercises, variation is the key depending on what part of the chest you want to hit.
Be sure to switch them up from time to time if only to spread out the wear on the joints.
OK hopefully this was of use to you and you learned something, be sure to leave a comment below.