Muscle Imbalance: Is Your One Arm Bigger or Stronger Than The Other?

Muscle imbalance is something that affects every one of us, even an ambidextrous person will still have one side of their body that is slightly bigger, or stronger than the other.

In fact, being born ambidextrous is incredibly rare, most people who claim to be ambidextrous now are people who were born left-handed but have trained themselves to be both through necessity.

This proves that it is possible to teach someone how to fix muscle imbalance, whether it be a right arm bigger than left, or one arm stronger than the other.

One thing that we should make clear, there are two forms of muscle imbalance, the first (which we are looking at) is an imbalance between different sides of your body. An arm that is bigger on one side or a leg that is stronger than the other.

The second form of muscle imbalance would be a bicep that is overworked in comparison to a triceps. Or a quadriceps that is bigger than a hamstring. This type of muscle imbalance can cause injuries, or hinder performance in sports, but it is another topic for another article.

Testing For a Muscle Imbalance?

The first thing that you need to do is establish how big the imbalance is, there are three tests for strength that you can perform; concentric, eccentric, and isometric.

These are three forms of muscular contraction and are excellent indicators of arm or leg strength. Let’s say that you are concerned that one arm is bigger than the other, specifically the bicep muscle.

Testing Concentric Strength

To test concentric strength (shortening of the muscle) you would hold a dumbbell in one arm and curl the weight up using perfect form. Check that your elbow is locked in place, and that you are not arching your back throughout the movement.

Once you have managed to perform this movement you would replicate it with the other arm. You would use progressively heavier weights until you can lift one weight with your dominant hand, but cannot match it with your non-dominant hand.

Testing Eccentric Strength

Once you have established the differences in concentric strength you can turn your attention to eccentric. This is the lengthening of the muscle, and it is actually a stronger position for your body.

Testing for eccentric strength is similar to concentric, if we use the bicep curl as an example again, you would this time start at the top of the movement (as if you had just curled the dumbbell up to shoulder height).

You will slowly lower the dumbbell down with as much control as possible. If the weight drops down too fast then you are not in control of the dumbbell and the weight is too heavy.

Again make sure that your posture and your technique are flawless. Compare both arms, and find out the maximum weight for each arm. If one arm is stronger than the other you will soon find out.

Testing Isometric Strength

The isometric test is perhaps the easiest to perform, for this you would hold a dumbbell in each arm at the halfway point of a bicep curl. The dumbbells and your forearms should be parallel to the ground.

Hold this position for as long as possible, eventually, one arm will tire before the other one does and you’ll know which arm is stronger.

Measuring your Muscles

Now you will have scores for the bicep in concentric, eccentric, and isometric strength. If you want you can repeat this with the triceps too as they also make up a large part of your arm size.

The next thing to do would be to measure the circumference of each arm in a flexed and un-flexed position. Remember that if you are measuring an arm or a leg there is more than one way to flex.

If you have one arm bigger than the other you should check bicep flexed, arm un-flexed, and tricep flexed. Then repeat the measurements with the opposite arm.

To check a muscle imbalance in your thigh you would measure your quadricep flexed, leg un-flexed, and then hamstring flexed. Note these measurements down and you will be able to assess how big of a muscle imbalance you are dealing with.

How to Fix a Muscle Imbalance?

Once you have established whether you have a muscle imbalance or not you can begin the journey to fixing your muscle imbalance. There are a number of different ways to fix a muscle imbalance, and we will take a look at them now.

Improving Your Form

One of the best ways to fix an imbalance is to look at your current training program. Are the exercises that you are performing being completed with perfect form?

If one side of your body is slightly weaker than the other then you may find yourself subconsciously favoring the stronger side. This can exacerbate the situation, as the weaker muscle is used less, while the stronger muscle is used more to compensate.

Concentrating on getting the perfect form, even if that means you have to lower the weight will really help you to address the muscle imbalance. Focusing on a good tempos will also improve your form and therefore reduce your muscle imbalances.

Exaggerating the eccentric part of a lift is a great way to improve your form and it will also help strengthen both sides of your body eccentrically.

Adding More Free Weight Exercises

If you are just starting out then using fixed resistance machines is a really good way to fix a small imbalance. But the longer that you train, the more you will find yourself needing to perform free weight exercises.

While a fixed resistance machine can help improve coordination at first, it can start to mask that imbalance when you get stronger.

Let’s look at a chest press machine for example. The two handles are often connected, and if you pushed the handle forward with just one hand, both handles will move forward.

This demonstrates how one side of your body can do more work than the other. If you swapped to a barbell bench press, you would also be able to let one arm take over slightly, but not to the same extent.

But if you were to perform a dumbbell bench press then there is absolutely no way that your dominant hand can take over. Both arms, pectorals, and deltoids would have to work equally.

This is why dumbbell bench presses are harder to perform, but they are fantastic for reducing muscle imbalances. You can do this with lots of exercises, replacing leg presses with barbell squats, leg extensions with lunges, or hamstring curls with Romanian deadlifts.

Perform More Unilateral Exercises

A unilateral exercise is one that works just one limb or muscle at a time, if a barbell bicep curl works both arms then a single arm bicep curl is a unilateral exercise. As you can imagine, adding a few unilateral exercises into your routine could really help balance your muscles.

Good examples would be single arm dumbbell shoulder presses, single arm bicep curls, single leg Romanian deadlifts, step ups, lunges.

The trick with unilateral exercises is to make sure that you start with your weak side first, there’s no point starting with your strongest side, managing 30 reps of bicep curls, and then only hitting 12 reps on your weak side. This will exacerbate the muscle imbalance.

Start on your weak side, hit your 12 reps, and then match it with your stronger side.

Keep Measuring, Be Patient

You should retake measurements of strength and size every six weeks or so to gauge progress.

This is one of the biggest mistakes people make, they fail to track progress and have no idea if what they are doing is effective or not. Keep taking measurements, checking strength and you’ll know.

The final piece of advice is to be patient.

These muscle imbalances did not pop up overnight, if your right arm is bigger than your left then this is because of years of favoring your right. You CAN remove that imbalance (or make it so small as to barely notice) but it will take time.

A lack of patience will ruin your chances of success, create small and measurable goals, hit them and then reset the goals again.

Final Thoughts

If you have one arm stronger than the other or one arm bigger than the other you could be forgiven for panicking. But it is a very common issue. Take your measurements so that you can see how serious the issue is.

Look at improving your form, improving your tempo, and picking better exercises that will suit your needs. Retake measurements as often as possible, and don’t try to rush things.

Symmetry is important for a lot of sports and in bodybuilding. But there will always be a very slight imbalance, provided you have a dominant hand (right or left).

If you have any questions about how to fix muscle imbalances, or if you are worried about your right arm being bigger than the left, feel free to leave a comment below.