Left arm bigger than right arm? (How to fix this)

left arm bigger than right arm

Why is my left arm bigger than right arm?

This is very prevalent, and anybody who lifts weights will notice that one side of their body is dominated by the other. I will show you how to solve it in two simple steps if one part of your body is starting to get substantially bigger than the other (whether it is your biceps, triceps, or any of the sides of your chest or lats).

Do you have a biceps on your left that is noticeably smaller than the one on your right? Is one side of your chest more developed than the other? Figure out what is wrong and how to fix it.

They are in everyone’s possession. You notice them sometimes, and sometimes you don’t. However, the fact that one side is smaller or less developed than the other is not unusual!

Genetics, low circulation or infection (which is essentially the number of nerves going to the muscles), smaller muscles, previous injuries, or even minor physical differences can all contribute to this.

The techniques listed below will help you work out those body parts for good!

Many methods work by increasing the amount of training, while others work by developing resistance or focusing on the physiological cause of the difference.

You are not alone if one of your biceps is larger than the other. Here’s what is causing the problem and how to resolve it.

Is it normal to have the left arm bigger than the right arm?

One eye may be significantly bigger than the other, or one leg may be slightly longer. It is perfectly normal for one bicep to be larger than the other.

The asymmetry is more noticeable when it comes to muscle size. The main reason for the muscle size disparity is that we are paying attention and keeping track of our progress. There are, however, preventable factors that can influence the variance and make it more pronounced over time.

Why is the left arm bigger than the right arm?

One biceps may be larger than the other for a variety of reasons. Natural dominance, inherent cuts and bruises, and careless training form are three likely causes.

  • Dominant hand

One of the most common reasons for one arm being larger than the other is because of your dominant hand. You use your dominant hand for more activities than your non-dominant hand throughout the day.

Carrying groceries or picking things up off the floor on a daily basis adds up over time. Your dominant arm muscles are intuitively more active, resulting in a size difference.

  • Tendon Injury

An inherent injury could also be causing a disparity in the size of your biceps. It can affect how your bicep looks when flexed if you have a muscle or tendon problem that has not healed thoroughly.

Tendon injuries are common and can happen during seemingly innocuous activities. Overtraining or incorrect form can cause the biceps tendon to snap with relative ease.

When a biceps injury heals without surgery, it frequently realigns in the wrong place, resulting in a mound. As a result, the bicep appears to be much smaller than the opposite arm.

  • Cheating Movements

Working with proper form during training has a significant impact. You could be cheating and allowing other body parts to pick up the slack without even realizing it by using other body parts to assist in the movement. Compensation occurs when muscles other than the ones you are targeting take over.

Also, in terms of one hand being stronger than the other. For example ,If your right hand is bigger and more powerful than your left, it will compensate for the weakness of your left arm by carrying the load. As a result, the stronger hand will continue to strengthen, highlighting the disparity.

What to do if the left arm is bigger than the right arm than the other?

  • Know Your Compensation

First and foremost, you must be conscious of your compensation and in tune with your body. You can rest against a wall for balance if you know you cheat the movement and keep your back occupied during hammer curls.

Use self-recorded videos or work with a coach to help identify imbalances and create opportunities for improvement. Training in front of a mirror can also be helpful during biceps exercises.

  • Use Unilateral Exercises

One way to correct muscle imbalance is by doing unilateral exercises, working each arm individually to properly isolate them. Swap your barbell curls for dumbbell curls and use more single-arm bicep exercises.

You can avoid your stronger arm picking up the slack of your weaker hand if you take this approach. To help build strength and muscle over time, vary your training and do a few

  • Start with the weak arm first

Your first set will be done with your left hand. If you reach muscle failure after 6 reps, switch to the right arm for the second set and stop at 6 reps as well. Even if you can do 3 more reps with your right arm, you will only be able to complete 6 reps.

When you use this method, your weaker arm receives more stimulation as you approach failure while resisting with your tougher arm. It basically allows you to keep your dominant side in shape/strength while still holding the weaker side.

  • Targeted negative

Negative training for the relatively weak side part should be added to each body part exercise.

The preacher bench is one of my favorite ways to do biceps negative training. You can stabilize your upper arm quite efficiently on the bench than you can on the floor.

This approach will assist in the development of strength in the target muscles, thereby assisting in the resolution of innervation issues caused by lagging development.

  • Targeted High Rep Training

Begin each body part’s workout with a light, high-rep set to target the weaker side muscles. Start each triceps workout with a set of high-rep single-arm pushdowns, for example, if your right triceps is small or weak. In this case, high-reps means 50 or more reps.

This high-rep set will improve the ability to gain mass by increasing circulation to the target muscle. This increased circulation means more blood is available, which means more nutrients are delivered to the muscles, resulting in increased muscle growth.

Exercises to do if your left arm is bigger than the right arm

Single-Arm Preacher Curl

Preacher curls, like the concentration curl, help to avoid shoulder shift while curling, and they are a great isolation workout for really targeting each arm independently.

How to do:
  • Sit on a preacher’s bench or lean on a bench that has been adjusted to armpit level. With an underhand grip on the dumbbell, rest your arm on the bench, stopping just below the armpit.
  • Swing the weight upwards slowly while keeping your upper arm fixed on the bench.
  • Stop and squeeze your biceps when your forearms are perpendicular to the ceiling.
  • Slowly return to your starting position.

Curl Dumbbells on an Incline

Incline dumbbell curls are great for targeting the biceps’ long head.

How to do:
  • Make a 45-degree angle with your bench. Grab a dumbbell in each hand with an overhand grip and sit on a bench.
  • Curl a dumbbell slowly, only allowing the forearm to move.
  • The key to this movement’s success is to move slowly and deliberately.

Lying Cable Curl

  • It may seem awkward to lie down for a cable curl, but it is a great way to target the biceps.
  • When done unilaterally, this exercise is crucial if one of your biceps is larger than the other.
How to do:
  • Connect the low pulley cable machine to the straight bar or EZ bar. Ropes can also be used.
  • Lying down on an exercise mat curl the bar slowly to your chest using an underhand grip.
  • Try squeezing at the top of the motion and return to the starting position slowly.
  • If you do not have access to a cable machine, you can substitute a resistance band secured to a rack for this exercise.

Single-Arm Reverse Cable Curl

The reverse cable curl is a biceps workout that is usually ignored. Start with a light weight for this exercise, which can be quite perplexing.

How to do:
  • Place the D grip on the cable machine with the low pulleys.
  • Face the machine with an overhand grip on the handle. Assume an athletic stance with your feet hip-width apart and your knees bent slightly.
  • Keeping your elbows and upper arm still, curl the weight toward your shoulder.
  • Pause, squeeze, and gently push back to the starting position at the top of the movement.
  • As a reminder to stay firm and steady, place your passive hand on your stomach.


Try these exercises if you have underdeveloped muscles on one side of your body. They can assist you in resolving differences between your two sides more quickly.