- A muscle imbalance is a noticeable size or strength discrepancy between muscle groups, such as having a right bicep that’s larger than your left, or a bigger upper body than lower body.
- The most common causes of muscle imbalances are improper workout programming and poor exercise technique, mobility, and flexibility.
- To fix muscle asymmetry, train your weaker muscles more and don’t do more reps with your stronger muscles, and to fix muscle disproportions, follow workout routines that emphasize the major muscle groups you want to improve.
Let’s face it.
One of the biggest reasons to toil away in the gym is to look good. Really good.
Most of us guys want a big, broad upper body, bulging biceps, washboard abs, and a thick, strong lower half.
Gals usually want lean legs, a curvy butt, and a toned upper body and abs.
And if you listen to the correct people, you’ll discover getting there isn’t all that hard.
Get your calories and macros right, follow a well-designed workout program, take the right supplements (or not), and just put in the work, and you’ll gain muscle and lose fat like clockwork.
Unfortunately, that doesn’t mean you’ll wind up with the physique you want.
In time, you might notice one side of your chest is smaller than the other, or one arm, or one leg, or heck, maybe even one side of your body.
Many people say this shouldn’t happen if you’re following a halfway sensible workout routine. Others say it’s purely genetic. Both are wrong.
You can develop muscle imbalances with any weightlifting routine, good or bad, and you can take measures to correct them.
It’s easy, too.
You don’t have to change your training drastically or buy special equipment.
As you’ll see in this article, all you have to do is make some simple tweaks to your training routine, monitor how your body responds, and adjust accordingly.
Let’s get to it.
- What Is a Muscle Imbalance?
- What Causes Muscle Imbalances?
- How Do You Spot a Muscle Imbalance?
- How to Prevent Muscle Imbalances
- How to Fix Muscle Imbalances
- How to Fix Muscle Asymmetries
- How to Fix Muscle Disproportions
- The Bottom Line on Muscle Imbalances
Table of Contents
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What Is a Muscle Imbalance?
Almost every major muscle in your body has a twin.
- Left pec, right pec
- Left quad, right quad
- Left triceps, right triceps
- Left lat, right lat
- . . . and so on.
Thus, one type of muscle imbalance is a size or strength discrepancy between a pair of muscle groups.
For example, it’s common for guys to have one arm or pec that’s larger than the other.
Bodybuilders refer to this as “asymmetry.”
Sometimes you can see these imbalances in the mirror, and sometimes you can’t, but you often notice them in your training because one limb is stronger than the other.
For instance, if one hand ascends faster than the other on your bench press, it may be because of one or more muscle imbalances on the slower side.
Another type of muscle imbalance can exist between pairs of major muscle groups, like your chest and back, triceps and biceps, and upper legs and calves.
If any of the muscles in these opposing pairs are smaller or weaker and less developed than the other, visual symmetry and performance suffers, and sometimes, the risk of injury rises.
Bodybuilders call this “disproportion.”
For example, overdeveloped chest muscles and underdeveloped back muscles not only spoils your “aesthetics,” it may also increase the likelihood of hurting your shoulders.
Similarly, if your hamstrings are weaker than your quadriceps, this may increase your risk of a hamstring injury.
For example, overdeveloped and under-developed not only knocks your “aesthetics,” it may also increase the likelihood of hurting your shoulders.
Similarly, if your hamstrings are significantly weaker than your quadriceps, this may increase your risk of a hamstring injury.
So, the goal is twofold:
- Symmetrical-looking muscles on each side of your body
- Proportionate development of the upper and lower and front and back parts of your body
Fortunately, 80% of this is following a well-designed workout program that focuses on heavy barbell training and that doesn’t neglect or undertrain any portion of your body.
The other 20%, however, depends on your genetics.
We all have strong and weak points that need to be addressed.
For me, my chest and biceps have always been high responders, while my lats and calves have been more stubborn than a radioactive mule.
Summary: A muscle imbalance is a noticeable size or strength discrepancy between muscle groups.
This can take the form of an asymmetry—where a muscle on one side of your body is larger than the other—or a disproportion, where one or more opposing muscle groups are significantly larger than the other.
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What Causes Muscle Imbalances?
The most common cause of muscle imbalances is training one muscle or muscle group more, or more intensely, than another.
For example, if you do more reps on your dumbbell curls with your strong arm than your weak arm, it will wind up bigger and stronger.
Similarly, if you hit your chest with 100 heavy reps per week and your back with only 30, or if you focus all of your time on your upper body and neglect your legs, you’ll develop a disproportionate physique.
These types of scenarios usually stem from poor workout programming.
Many workout programs for men emphasize the “mirror muscles” (chest, shoulders, and arms), and overlook the rest (back and legs).
A good program, however, intelligently distributes the work between your upper and lower regions, and among pressing, pulling, and squatting exercises.
Another common mistake that produces muscle imbalances is using one side of your body more than the other on various exercises like the squat, deadlift, and military press.
Many people aren’t focused on the task at hand while they train and let their mind wander. This prevents the “mind-muscle connection” that many bodybuilders talk about, and often results in one side of the body (the stronger one, normally) doing more work than the other.
For example, let’s say your left back muscles are less developed than your right. You don’t realize it, but while doing dumbbell rows with your left arm, you’re using more shoulders and momentum to swing the weight than you do with the right. Thus, every time you row, the right side of your back does more work and grows faster.
Poor flexibility and mobility often prevent people from doing exercises properly, even if they want to.
Many of us spend our days sitting or hunched over a desk, which makes it easy to develop tight shoulders, hip flexors, and lower back muscles that can’t perform well in the gym. Our body compensates in several ways, which can result in certain muscles being over-engaged with others being under-engaged.
Summary: The most common causes of muscle imbalances are improper workout programming and poor exercise form, mobility, and flexibility.
How Do You Spot a Muscle Imbalance?
The easiest type of muscle imbalance to spot is asymmetry.
All you have to do is grab a measuring tape and compare.
I like to measure muscles flexed for this analysis, because it results in more accurate numbers (you’re less likely to depress the muscles with the tape and throw off your measurements).
Proportions are much trickier to judge, however, because it’s at least partially subjective.
I might think a guy’s biceps are too big for his shoulders, but someone else might think it looks awesome. That said, if you take cold, unflexed pictures of the front and back of your body, and analyze the relationships between your upper and lower halves, and front and back muscles, you’ll probably find flaws.
This is especially true if you’re training one side or half of your body harder or more than the other. If that’s the case, you have at least a minor imbalance.
If you’re a guy, you can also see how you measure up against the physical standards given in this guide to building an ideal-looking physique, determine what you most need to improve, and address it in your training.
(No such guidelines exist for women that I know of, but if you’ve come across anything, please drop a link in the comments below!)
You can also use this guide to help estimate your genetic potential for developing different muscle groups to see where you have the most room for improvement.
Summary: To spot a muscle asymmetry, measure your flexed limbs on your right and left side and compare the measurements. To spot a muscle disproportion, take pictures of your body from different angles and see if there are any parts that seem too large or small compared to others.
How to Prevent Muscle Imbalances
The first step to preventing muscle imbalances is following a workout program that’s built on compound exercises that train your entire body evenly.
For instance, if you want to train your legs, you can do something like the leg extension, which works only your quads, or you can squat, which works all the muscles in your legs and engages just about every other muscle in your body too.
The same goes for every major muscle group.
You can do an exercise that isolates it, strengthening little else, or you can do one that focuses on it, but strengthens others as well. And the more you do of the latter, the more uniformly your body will gain muscle and strength. That doesn’t mean you won’t develop muscle imbalances, though.
First, you’ll favor one side of your body more than the other in certain exercises.
You can do an exercise that isolates it, strengthening little else, or you can do one that focuses on it, but strengthens many others, as well. And the more you do of the latter, the more symmetrically your body will.
Unfortunately, that doesn’t mean you won’t develop muscle imbalances, though.
First, you’ll inevitably favor one side of your body slightly more than the other in certain exercises.
You might extend one arm just a tad further during your bench press, or angle one foot out more than the other while squatting and deadlifting. Over time, these habits can add up to slight, albeit significant, differences in size and strength.
This is one reason why many weightlifting programs include unilateral exercises, which are movements that train one limb at a time (single-leg or single-arm movements), like the dumbbell lunge, alternating dumbbell curl, and Bulgarian split squat.
These types of exercises negate the physiological biases that can creep into bilateral exercises, which train both limbs simultaneously (like the barbell squat, barbell bench press, and barbell deadlift). With unilateral exercises, each limb must “pull its own weight.”
Another effective way to prevent muscle imbalances from developing in your body is to follow a mobility routine.
If your body isn’t flexible and functional enough to perform an exercise correctly, the compensations that result will, in time, cause muscle imbalances.
For example, I’ve struggled with tight hip flexors, and when one side was tighter than the other, I couldn’t help but favor the looser one when squatting heavy weights.
If I had done nothing to correct this, I not only would have increased my risk of injury, but one of my legs would have wound up more developed than the other.
I’ve fixed it each time with a simple mobility routine like this, and have now gotten better with keeping it in as a matter of routine, as opposed to a corrective action.
If you do just 15 minutes of mobility work once or twice per week, you might be surprised at how much it can help your performance in the gym.
Check out these articles to learn more about effective mobility routines:
⇨ The Definitive Guide to Mobility Exercises: Improve Flexibility, Function, and Strength
⇨ How to Improve Flexibility and Mobility for Squatting
⇨ How to Improve Shoulder Flexibility and Mobility
⇨ My Daily 10-Minute Yoga Routine for Better and Safer Workouts
Summary: The three best ways to prevent muscle imbalances are to follow a workout program built on compound exercises that trains your entire body evenly, incorporate unilateral exercises into your program, and improve your flexibility and mobility.
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How to Fix Muscle Imbalances
So, you have a muscle imbalance.
You know what to do and not to do going forward to prevent further issues, but now we have to get you back on track.
As you know, there are two kinds of muscle imbalances, and they require different solutions.
How to Fix Muscle Asymmetries
If one side of your body is bigger or stronger than the other, the solution is obvious: train the weaker one more.
The easiest way to do this is to increase the weekly volume (reps or sets) on the weaker side. I like to go up by 25 to 35 percent.
For example, let’s say your left shoulder is smaller than your right, and you do about 30 reps of dumbbell side lateral raises per week per side (three sets of 10 reps).
You could then bump your left-side raises up to 40 reps per week by adding one additional set to your shoulder workout for your left arm only (three sets on your right, four sets on your left) and continue this way until your left shoulder catches up.
You should also end your sets on unilateral exercises when your weak side fails. In the case above, that would mean stopping the lateral raises when your left can’t go any farther, regardless of how much more your right can do.
By doing this, you keep from racking up more volume on your stronger side.
It also helps to start your sets with your weaker side. That way, you’re allowing your weaker part to determine when you stop your sets, not your stronger one.
Continuing with the shoulder example, you might only be able to do 8 reps per set with your left arm when doing dumbbell side raises, even though you could do 10 or 11 with your right arm. Here, you’d still only do 8 reps with both arms to keep their volume equal.
Summary: To fix muscle asymmetry, train your weaker muscles more and don’t do more reps with your stronger muscles.
How to Fix Muscle Disproportions
At bottom, the solution here is more or less the same as the above: you have to train lagging muscle groups more, or more intensely, than you’re training them (or both).
You can achieve this by increasing weekly volume, or by working with heavier weights and pushing hard for progressive overload.
So, let’s say your legs are still too small compared to your upper body, despite following a well-balanced weightlifting routine.
Maybe you neglected your legs and now have an imbalance between your upper- and lower-body development, or maybe your lower body just didn’t respond to the training as well as you had hoped.
Either way, if you change nothing about your workout programming, you’ll be stuck with this imbalance for quite a while.
The solution is to train your legs harder, but that doesn’t mean adding another leg workout on top of what you’re already doing.
Instead, you’ll probably need to dial all the rest of your training back to “make room” for the additional leg work, especially if you’re doing a lot of heavy, compound weightlifting (as you should be)!
This will allow you to focus on maximal leg development, without sacrificing any of the size or strength that you’ve developed elsewhere.
A training routine that’s designed in this way is called a “specialization routine.”
It’s built to push the envelope with one muscle group, while cutting back with others, so you can make sure you’re fully recovering.
Here are several examples of specialization routines that I’ve put together:
⇨ How to Get Bigger and Stronger Legs in Just 30 Days
⇨ How to Get Bigger and Stronger Biceps in Just 30 Days
⇨ How to Get Bigger and Stronger Triceps in Just 30 Days
⇨ How to Get Bigger and Stronger Shoulders in Just 30 Days
⇨ How to Get a Bigger and Stronger Back in Just 30 Days
⇨ How to Get a Bigger and Stronger Chest in Just 30 Days
If any of those muscle groups are lagging for you, work your way through their respective routines, and it should help.
Summary: To fix a muscle disproportion, first make sure you’re following a well-balanced workout plan that revolves around heavy, compound weightlifting. If that doesn’t fix the problem, follow a workout plan that emphasizes a major muscle group you want to improve.
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The Bottom Line on Muscle Imbalances
A muscle imbalance is a noticeable size or strength discrepancy between muscle groups, such as having a right bicep that’s larger than your left, or a bigger upper body than lower body.
The most common causes of muscle imbalances are:
- Following an improper workout plan, especially one that focus on certain muscle groups far more than others (80% upper body and 20% lower body, for instance).
- Sloppy exercise technique that causes you to unintentionally train one side of your body more intensely than the other.
- Poor mobility and flexibility, which can make it impossible to properly execute a number of exercises.
Sometimes, however, the culprit is merely genetics, which can cause one muscle group to grow much faster than another.
For instance, my chest and biceps have always been high responders and quick growers whereas my lats and calves have always been sluggish.
To help prevent muscle imbalances, follow a workout plan that revolves around heavy, compound weightlifting and gives plenty of attention to all major muscle groups. Incorporating unilateral exercises into your routine and improving your flexibility and mobility can also help.
To fix muscle asymmetry, train your weaker muscles more and don’t do more reps with your stronger muscles, and to fix muscle disproportions, follow workout routines that emphasize the major muscle groups you want to improve.
If you do all that, you’ll avoid muscle imbalances and not only improve your “aesthetics,” but reduce your risk of injury as well.
What’s your take on muscle imbalances? Have anything else you’d like to share? Let me know in the comments below.
+ Scientific References
- Petersen J, Hölmich P. Evidence based prevention of hamstring injuries in sport. Br J Sports Med. 2005;39(6):319-323. doi:10.1136/bjsm.2005.018549
- Page P. Shoulder muscle imbalance and subacromial impingement syndrome in overhead athletes. Int J Sports Phys Ther. 2011;6(1):51-58. http://www.ncbi.nlm.nih.gov/pubmed/21655457. Accessed October 14, 2019.