Sales Popup
Someone purchased a
6 hours ago





Your Cart is Empty

September 29, 2021 9 min read

Muscle imbalances in different parts of the body are normal. But for many people, the most notable imbalance can occur in terms of arm size.

If you find that you are developing bigger biceps and triceps in one arm than in the other, you might be a little concerned.

Here are a few of the factors that cause this to happen, and we’ll also look at some good ways of fixing the problem. 

PRO TIP: Get the most muscle building potential out of every workout with VEG-PRO, the best-tasting plant-based protein in the fitness world. Pick your flavor now!

Is it Normal for One Arm to be Bigger Than the Other? 

It is indeed a normal situation to find one of your arms more developed than the other. Asymmetry is a big part of nature, among humans as well as animals. For example, you might notice that a person has one ear that is slightly bigger than the other or one leg that is a little longer. 

In most cases, differences like these are so small that they often go undetected until you actually find out the size of your features with a tape measure. But because muscles can be quite prominent, the size of each muscle is sometimes quite noticeable and this makes the asymmetry more obvious. 

The main reason many bodybuilders start to notice any type of asymmetry in their muscle size is because they are paying a great deal of close attention to the size of the muscles and spending a lot of time tracking their progress. So even though some of this is natural, there are also a lot of other preventable factors that might influence the amount of asymmetry that you can see in your own specific muscles. 

What Are Some Preventable Factors? 

There are a lot of preventable factors that could be some of the reasons why one of your arms is developing quicker and looking larger than the other arm. The three most common preventable factors include improper training form, natural dominance, and the presence of underlying injuries.

1. Improper Training Form 

When you are doing weight training, it is vital that you use the proper form. It is not helpful to cheat the movements and allow your other body parts to take on more weight just so that you can finish your set. When other muscles take over the movement, it is known as a compensation. For example, if you start getting tired while doing barbell curls, it might be tempting to allow your shoulders and traps to help you out. 

Even though you might still be able to complete the movement, it will not have as much of the desired effect. The same effect also applies when one of your arms is stronger than the other. Your right arm will compensate for the left arm’s weakness and simply bear the brunt of the weight. This will lead to the strong arm getting stronger, and it will make the asymmetrical difference even more noticeable. 

2. Natural Dominance

One of the biggest reasons why one arm might be larger than the other is related to your dominant side. When they are lifting weights, almost everybody is going to develop a weaker side and a stronger side, with the weak arm generally being on the left side for most people.

Throughout all of your daily routines, you will probably use your dominant hand to do more things than your non-dominant hand. All of those daily tasks, such as moving groceries or picking things up off the floor, tend to add up over the course of the day. This leads to the muscles in your dominant arm naturally getting more exercise, and this can result in differences of size in your weak side. 

3. Underlying Injuries 

Another reason you might be discovering an imbalance in your arm size is an underlying injury. For example, if you have ever had a muscular or tendon issue that did not heal properly, it can impact how your arm looks when you are flexing. These types of injuries are fairly common and they can even happen during your daily routine. Simply carrying something the wrong way can snap a bicep tendon quite easily.

3d illustration of human elbow injury, medical concept.

Overtraining can also lead to these types of torn bicep tendons, which is another reason to allow yourself enough rest and recovery. If your arm injury is allowed to heal without corrective surgery, it can sometimes reattach in the wrong place. This causes a bunched appearance, so that the muscle no longer extends from the shoulder to the elbow. This can make the arm look significantly smaller than the other one. 

Some Good Ideas

What are some simple things you can do on a daily basis if you start to notice a significant difference between the size of your arms and would like to reduce the difference? Here are a few very simple training factors for you to keep in mind as you continue to follow your workout program.

Slow Down Your Movement 

Physics plays a subtle but important role in your weight training. Doing a bench press of a 40 pound weight quickly can feel very different than lifting that 40 pound weight slowly. There are a few factors that contribute to these differences, and the biggest of these factors is momentum. By slowing down the movement and adding a lot more torque, you can be sure that the muscle is doing the work rather than relying on momentum.

Know Your Compensations 

Always be aware of your compensations. If you know that you cheat the movement and let your back take over during bicep curls, you can lean against the wall for balance. By doing things like this, you are preventing your body from making swinging motions that transfer the movement from the biceps to the traps. 

Take a few videos of yourself or work with a personal trainer to help you identify some of the muscle imbalances in your movements and to help you find ways to improve your form and ultimate muscle growth. Of course, it can also always be quite helpful to train in front of a mirror during your bicep exercises. 

Use Unilateral Exercises 

One of the most effective ways to even out biceps is to use unilateral exercises. In other words, this is when you work one arm at a time in order to isolate the biceps on each side. You might decide to exchange your barbell curls for dumbbell curls and use more single-arm bicep exercises. By doing something like this, you can prevent your stronger arm from doing more work than your weaker arm. 

You can also experiment with your training and do a few extra reps with the weaker arm to help build a lot more strength and muscle mass over time.

These exercises can be performed with  high loads or training volumes to help you produce the kind of overall muscle and strength gains you might be looking for.

Use Resistance Bands 

Using resistance bands instead of weights for some of your exercises can also really help you balance out the size of your arms. When you curl with a dumbbell, you may notice that the weight seems lighter at the top of the movement. With a resistance band, the more you stretch it, the greater the resistance will be.

At the top of the concentric part of the movement, you will feel a lot more resistance when using the band and the eccentric movement will become easier. This is known as flipping or inverting the strength curve, and it can really help balance out the size of your arms.

Some Helpful Exercises

You also might find these exercises in your workout program to be very useful when it comes to reaching better health and gaining better overall mobility. In addition to all of the simple training factors that we have mentioned above, there are some really good exercises that you can start doing if you are finding that one of your arms is developing faster than the other one. Here is a short description of each of those helpful exercises.

Concentration Curls 

Concentration curls remove the momentum from your movement and prevent any of that movement from shifting to your shoulders. This type of isolation will allow you to focus on each arm separately and correct any bicep imbalances that you may have developed. 

Strong Athletic Asian Man workout with dumbbell curl Concentration

Follow the list of steps below to get started with this exercise:

  • Sit on a bench with your feet firmly on the ground. 
  • Hold a dumbbell with your elbow resting on your inner thigh in a supinated hold. 
  • Slowly curl the weight up toward your bicep.
  • Your upper arm should be stable with only your forearm moving. 
  • At the top of the movement, pause and squeeze your bicep. 
  • Slowly lower yourself back to the original starting position.  
  • Take your time and move through this exercise slowly for best results. 

Incline Dumbbell Curl 

Incline dumbbell curls are some really good ways to target the long head of the bicep muscle. The increased range of motion in this exercise sets it apart from many of the other curl variations that you might have done.

Follow the list of steps below to get started with this exercise:

  • Adjust your bench to a 45-degree angle. 
  • Hold two dumbbells with an underhand grip, and sit back on the bench. 
  • Slowly curl one dumbbell, allowing only the forearm to move. 
  • At the top of the movement, pause and squeeze the bicep. 
  • Slowly lower the dumbbell back to the starting position.
  • Repeat the movement on the other side. 
  • It is vital to do this exercise in a slow and controlled way. 

Single-Arm Preacher Curl 

Much like concentration curls, these types of preacher curls can help prevent any type of shoulder shift when you are curling. Single-arm preacher curls can be a good isolation way to target uneven biceps.

Follow the list of steps below to get started with this exercise:

  • Sit at a preacher bench or lean over a bench adjusted to armpit height. 
  • Hold a dumbbell with an underhand grip and rest your arm on the bench, stopping just under the armpit. 
  • Curl the weight up slowly while keeping your upper arm fixed on the bench. 
  • When your forearm is perpendicular to the ceiling, pause and squeeze. 
  • Slowly lower yourself back to the original starting position. 

Lying Cable Curl 

Laying down for cable curls may seem like a strange idea, but it can be a good way of preventing motion transfer and effectively targeting the biceps. When performed unilaterally, this exercise can be very effective if you have one arm that is bigger than the other.

Follow the list of steps below to get started with this exercise:

  • Attach a straight bar or EZ bar to the low pulley cable machine. 
  • You can also use ropes or a D grip for unilateral movements. 
  • Lay on your back with your feet toward the cable pulley and grip the bar with an underhand grip, keeping your arms extended. 
  • Curl the bar upward toward your chest while keeping your upper arms tucked to your sides and still. 
  • Squeeze at the top of the motion.
  • Slowly lower yourself back to the original starting position.
  • If you are not able to find a cable machine, you can do this movement with a resistance band secured to a rack. 

Single-Arm Reverse Cable Curl 

The reverse cable curl is a useful bicep exercise that is very often overlooked and underrated. It is best to start with a light weight for this movement, which can be surprisingly deceptive in terms of its difficulty.

Follow the list of steps below to get started with this highly effective exercise:

  • Attach a D grip to the low pulley cable machine. 
  • Grab the handle with an overhand grip while facing the machine. 
  • Assume an athletic stance with feet at hip-width and knees slightly bent. 
  • Curl the weight up toward your shoulder, while keeping your elbows tucked and upper arm stable. 
  • At the top of the movement, pause and squeeze.
  • Slowly lower yourself back to the original starting position. 
  • Brace your core and keep your chest up for this entire workout. 
  • Try resting your inactive hand on your abdomen if you want to stay firm and stable.

Resting and Recovering

To really keep building your muscles, you need to allow your body enough time to rest and recover for up to 48 hours before you train the same muscle groups. You will be sure to find that rest and proper nutrition are very important when it comes to reaching your weightlifting and bodybuilding goals.

Some Final Things to Consider 

It’s completely normal for bodybuilders to have one arm develop faster than the other when they have been lifting weights. However, lots of people also want to know how to balance out their arms for an even appearance. The first step is to identify any issues that may be causing the imbalance.

Next, use all of the unilateral exercises with a proper form to isolate each arm and fix muscle imbalances. With enough time and effort, you will find your arm muscles starting to even out.

PRO TIP: Get the most muscle building potential out of every workout with VEG-PRO, the best-tasting plant-based protein in the fitness world. Pick your flavor now!