Out of Proportion Chest and Arms


Hello, I'm 6'1" 195 pounds and have been consistently lifting since high school (10 years). I workout 3 days/week, in a chest/back/arms split.

My arms are very muscular and quite out of proportion with my chest, as it is quite undeveloped. My chest workout has always been the workout I focus on most.

I do 4 exercises with 3 sets a piece...generally flat, incline, decline bench with a fly exercise. I only do 2 exercises per arm muscle (shoulder, bicep, tricep).

I cant understand how my arms develop muscle so easily while my chest has so much difficulty.

Is there something i can do to get my chest caught up to my arms?

Answered By:

Mike Behnken, MS, CSCS ANswers the Fitness Question

Qualifications of Mike Behnken


It is very easy to see why your arms are so much more developed than your chest and that is because every exercise in your split is essentially working on the muscles of your arms.

Compound exercises such as bench presses, rows, shoulder presses and lat-pull downs have prime movers and synergists which are responsible for the joint motions.

Even though you're working "chest" when you're doing bench presses, your triceps are performing a significant portion of the work. You can see this by looking at the motion of your elbows during a bench press as they extend around 90 degrees. This 90 degrees extension is around the same as doing a high cable triceps extension but the triceps are likely under significantly more tension.

You explain on your chest day you're doing 9 sets of various bench presses. This amounts to basically doing 9 sets of triceps extensions. The same goes for the biceps when you're doing lat pull downs and rows. Back exercises also work the long head of the triceps to some degree.


Building the Chest:  Exercise Form is Essential

Like I mentioned before, every time you perform a chest press, your triceps are lifting some of the weight. This can be exacerbated greatly by your exercise form.  retracted scapula

If you are using exercise form which is inconsistent with your goals your current workout split could equate to basically doing 3 workouts of all arm exercises with only 1 single set for the chest (flies).

In order to greater emphasize your chest during pressing exercises you must keep your shoulders retracted during the motions. This involves forcefully squeezing your shoulder blades together as shown in the photo.

If you haven't been doing this, it is likely the prime reason why your synergists (arm muscles) are overdeveloped while your chest is underdeveloped. You likely have synergistic dominance which is a postural distortion pattern in which the muscle fibers of your prime movers are inactive and dormant because they are not needed during the motions which are dominated by the synergists (triceps, biceps, anterior deltoids).

Ways to Attempt to Improve your Proportions

Exercise Selection

You will never totally isolate your chest during any pressing exercises. To isolate your chest you need to more chest flies emphasizing proper form to isolate the chest.

Performing 9 sets of various presses is not the way to go if you want to build your chest. A better option is to perform 3 sets of one angle of bench press followed by various angles of chest flies on dumbbells and cables.

If what has been mentioned previously is not the case, you may simply just have to lay off the arm exercises. Unless you're a competitive bodybuilder, having an arm day is pointless. Give your upper body a day of rest and work your legs which is far more beneficial to your whole body than doing biceps curls and triceps extensions.


If you do indeed have synergistic dominance of your triceps, it may be due to poor posture. If your shoulders are protracted (rounded forward) the first step is to begin lengthening your pec muscles by static stretching. You may need some time off to correct your posture before you efficiently build your chest muscles. For more information check out Muscle Imbalances and Posture Problems.

Balance out your Routine

If you have been working out non-stop for years, take a rest. If you haven't did a set of squats in a year, start doing a leg day. If you have been laying off of cardio, start doing it.

Over working a muscle group can be an annoying proportion now when you're young but it can turn into a debilitating problem as you get older. Your muscles have the power to change the shape of your skeleton and over time misalignments can cause joint problems. Working out is beneficial but it can also cause problems if you don't do it smart.

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