What Should I Do if One Arm is Bigger than the Other?

When it comes to our anatomies, you’ll find that it’s incredibly rare for a person to have a completely symmetrical physique. Muscular imbalances are perfectly normal and they’re especially noticeable in the arms. 

Most people have one arm larger than the other, and 9.9 times out of 10, the larger arm is that person’s dominant arm. For most, these differences in size are barely noticeable, but for some this is not the case. 

If you have one arm which is noticeably larger than the other, here’s a look at what you can do to even things out. 

How do you know if you have a muscle imbalance?

As we mentioned, muscular imbalances are pretty common, but what are the warning signs? Well, let’s find out, shall we? 

Here are some common signs of a muscular imbalance:

  • Poor posture 
  • A noticeable difference in muscle size and definition 
  • Noticeable difference in strength, mobility, and balance on just one side of the body 
  • Favoring one arm (muscle) over the other 
  • Pain or discomfort not connected to a sporting or training injury 

Is it normal to have one arm bigger than the other?

A lot of people dealing with muscular imbalances may wonder whether or not it’s normal to have one arm larger than the other, and the answer is yes. 

Nobody out there, not even the most aesthetic bodybuilders, have a completely symmetrical physique and asymmetry therefore, is a part of everyday life. 

In terms of muscle size, I.E the arms, often the main reason why we find that one arm is larger than the other is because we use our dominant hands and arms more. Sure, you may train both arms exactly the same in the gym, but if you’re constantly picking things up, putting them down, twisting, and moving things with your dominant arm every day, over time your muscle mass will increase slightly and the difference in size will really become apparent. 

Do muscle imbalances fix themselves?

If you’re dealing with a muscle imbalance, the issue won’t fix itself, unfortunately, as that will be down to you. 

If you are affected by a muscle imbalance, the good news is that there are a series of things you can do to help fix these issues, which we’ll be looking at in more detail shortly. 

Long story short however, muscle imbalances do not correct themselves, but they can be rectified by you. 

How to fix uneven arm muscles

As previously mentioned, if a muscular imbalance in the arm is affecting you, there are things you can do to put this right. 

Here’s a look at several things you can do to help correct uneven arm muscles:

Perform unilateral exercises when training 

When working the biceps, it has to be said that barbell and EZ bar curls are one of the most effective biceps exercises in existence. However, if you’re dealing with a muscular imbalance, unilateral exercises are the way to go. 

A unilateral exercise is basically an exercise that is performed with one side of the body at a time. Rather than barbell or EZ bar curls, perform single-arm dumbbell curls as this will ensure that your weaker arm works just as hard as your stronger arm, rather than having your dominant arm do the majority of the work. 

Slow each rep down

Rather than swinging the weights and performing each rep with a fast pace, try slowing things down instead. 

If you ordinarily curl 15 pounds with a fairly quick tempo, try slowing things down and you’ll notice just how different 15 pounds feels now.

Slowing down the rep takes momentum out of the equation and ensures that the muscle, including the weaker muscle, does the majority of the work. 

Take your weaker arm to failure and then stop 

Training to failure is generally a very beneficial way of training for muscle hypertrophy (growth). The problem with a muscular imbalance however is that most people train until their dominant arm hits failure. 

Instead of doing this, instead, train until your weak arm reaches failure, and then stop. This ensures that both arms are working equally as hard. If you trained until your dominant arm hit failure, you’d likely need to swing the weight and use momentum to get the weak arm to complete a rep, whereas the dominant arm would be stricter and would therefore get more work. 

This method of training will allow your weak muscle to catch up. 

Resistance bands instead of dumbbells 

Another very simple and effective hack for anybody dealing with a muscular imbalance in the arm is to switch up dumbbells for resistance bands. 

When performing dumbbell bicep curls, you’ll notice how the hardest part is curling the weight. At the top of the lift, once the muscle has contracted, the weight actually feels much lighter. If you curl a resistance band, however, the more it is stretched, the more resistance there is. 

At the peak of the concentric portion of the lift, a resistance band will provide significantly more resistance, making the exercise tougher. On the other hand, the eccentric part of the lift as you curl the band upwards, will be much easier. 

Experts call this ‘inverting the strength curve’ and it is a tried and tested method for balancing out muscular imbalances in the biceps. 

Focus more on your weaker arm 

If you’re dealing with a very noticeable imbalance, you may want to consider training your weaker arm much harder than your dominant arm. 

If you’re right-handed and you have a much smaller and weaker left bicep, work the left bicep harder than the right. You may wish to consider performing more reps with exercises that isolate specific muscle groups, such as concentration curls, and perform more reps with your left bicep perhaps? 

Begin with your weaker arm first 

Another simple, but very effective tip for correcting a muscle imbalance in the arm is to begin with your weaker arm first. 

9 times out of 10, when somebody performs a bicep exercise such as the dumbbell hammer curl, they’ll do the first rep with their dominant arm first. This is all well and good, but it typically means that once you hit failure with your right arm, you won’t be able to complete a rep with your left, which will only add to your imbalance. 

Final thoughts

As you can see, muscle imbalances in the arm are perfectly normal, and if you do have one arm bigger and stronger than the other, there are plenty of ways of correcting the issue without making any radical changes to your training.