Bodybuilders can be a tad neurotic at times. The kind of focus and discipline required to follow this path almost requires it, and when you start to notice muscular imbalances it’s easy to fixate on them. One common imbalance that lifters tend to obsess about is uneven pecs. Building an impressive chest is often the first goal of many male bodybuilders and it is the focal point of the physique when shirtless. Therefore it can be very frustrating when you notice that after all the hard work you are putting in at the gym your pecs are uneven and unattractive. There are a number of possible causes of this imbalance and identifying yours is the first step in fixing this issue.
What Causes The Chest To Become Asymmetrical?
Let’s delve into the anatomy of the chest to get a better understanding of how they could become even. As you can see, the pectorals consist of two different muscles. The pec minor is hidden beneath the pec major and is not visible. It originates from your 3rd-5th ribs and attaches to the scapula. The pec major is the part that you see and it can be further split into two parts. The upper fibers originate from the collarbone and the lower fibers originate from the sternum. Both are inserted at the humerus. This is why you are able to specifically target the upper or lower chest.
One possible cause of an uneven chest is that your muscles attach at different parts of the bone. This is IFBB pro Lionel Brown. He clearly has uneven pecs but it is not from a training or structural imbalance. His right pec major simply attaches to the outer part of the sternum bone while the left side attaches further to the inside, This results in a little extra muscle fibers on the inside bottom of the left pec. If this is the cause of your uneven pecs then there is unfortunately not anything you can do to change where your muscles attach to the bone.
Another possible cause is that one side is more hypertrophied than the other. If you feel a better mind muscle connection with one pec, you may be better at recruiting that side and as a result it grows more. Perhaps your shoulders or triceps are stronger on one side and take over from the pecs more than they should. Typically when one pec is more hypertrophied than the other, that same side’s shoulder is smaller than the other due to unbalanced recruitment patterns. A number of postural imbalances can change how you recruit your pectoral muscles.
In fact if your posture is really off, chances are your whole shoulder girdle is dysfunctional and out of whack. This can change the shape and size of your pecs. Think back to where the pecs attach. The part that attaches to the collarbone could be tight and short if the upper traps are tight resulting in a rolled forward shoulder posture. This could make it appear smaller.
Since both parts of the upper pec insert at the humerus, if the shoulder is excessively internal, one side of the pecs will be shorter and uneven from the other. A tight pec minor will also contribute to both the rolled forward and internally rotated position of the shoulder. These are all imbalances that must be addressed in order to optimally recruit the pectoral muscle fibers.
Step One: Loosen Up Tight Muscles While Strengthening Weak Ones
If your uneven pecs are not due to the attachment site, then chances are you likely have one shoulder more internally rotated than the other. To test this, reach around your back and see how far up your back your hand can go. Do not let your shoulder roll up or forward while doing this. If one side is significantly lower it is tight and lacking internal rotation. You must first address this issue or you will not be able to recruit your pec muscles evenly.
Spend extra time stretching and rolling or massaging your front delt, pec minor, underarm tissue, and upper trap muscle on the tighter side. You will also need to build up your rear delts and rhomboids to help bring your shoulder to a more neutral position. This will help your chest appear larger on this side by allowing the pectoral muscle to stretch to the new position of the insertion site. It will also help you better recruit your chest on your underdeveloped side, which is the next step in fixing this imbalance.
Conversely you may be lacking external rotation of the shoulder, which can make it difficult to to keep tension on the pecs during exercise, especially when reaching deep ranges on pressing movements. To test to see if one side is missing external rotation, simply lift up your elbows to shoulder height. Keep them even or slightly to the front of the shoulders and see how far backwards you can rotate the back of your hand. If one side goes noticeably further than the other then you know you have an issue. To address this you need to stretch and roll or massage your posterior delt, rhomboids, and underarm tissues of the tight side while strengthening your front delt, serratus, and pecs.
Step 2: Build Up The Weak Side
If one pec is bigger than the other you need to make sure it is not taking over on compound lifts. Switch to dumbbells and other unilateral movements to ensure the weak side is carrying its weight. You must be able to feel the pec muscles actually engage.
The mind muscle connection is vital when trying to target a weak area so you want to do everything possible to maximize it. This may mean using very light weights, or cables instead of free weights, or performing a partial range. Anything that allows you to become better connected to that muscle. Maximizing the blood flow to the muscle, or the “pump”, makes it much easier to feel the muscles working. So use higher reps, stretch the muscle between sets, and supplement with a pre workout proven to increase nitric oxide flow to the muscles like Sheer NO.
You may benefit from a little extra volume for the underdeveloped side as well. The best method for achieving this when trying to balance out the pecs is to first pick a unilateral exercise. Lets use the incline hammer press as an example.Start your set using both arms for 10-12 repetitions. At this point stop with the more developed side and pump out another 3-5 reps with the weak pec.
One thing that may help with recruiting the muscles from the weak side more effectively is to select isolation movements that completely remove other bodyparts. Your exercise selection should include things like cable crossovers, pec deck flyes, and low cable flyes to fully target both the upper and lower fibers of the pecs.
In addition to the above tips, also simply be aware of the position of your shoulders while lifting. Try to override compensations your body may wish to employ and keep the shoulder in a neutral position to keep it from taking over from the pecs. If you feel your form start to go, do not continue to perform compromised reps. Keep in mind that there is a certain amount of asymmetry that is acceptable and to be expected but it should not be enough to negatively impact your aesthetics in a significant way.
In your quest for a barrel chest don’t neglect your pulling muscles. If your program design has a disproportionate amount of pressing to pulling exercises then your posture will suffer and cause your pecs to become shortened and tight. Remember you want a nice open chest and wide shoulders where your pectoral muscle fibers can fully lengthen.
An uneven chest may not be something you can control if it is at the attachments on the sternum. If this is not the case then it is likely uneven due to a combination of compromised posture from muscular imbalances resulting in altered positions of insertion points and an inability to effectively recruit one pectoral muscle due to these imbalances. This means if the underlying issues are not addressed than you are likely compounding the problem and making it worse.
You should test for internal and external rotation on both sides as either can inhibit pec activation. Once the mobility issues are addressed you need to build up the weak side and strengthen the mind muscle connection to it by using unilateral exercises, performing extra volume, and including a large amount of isolation exercises. It can take months to completely fix the issue of uneven pecs but by following these tips you can make sure that when people stare at your bare chest it’s out of admiration and not because they are lacking symmetry.