Bodybuilders run into a lot of challenges when pursuing their goals. While nutrition and recovery are common concerns, imbalances are a silent issue that often goes unaddressed. For many bodybuilders, the most notable imbalance is in arm size.
If you have one bicep bigger than the other, you aren’t alone. Here’s what causes this phenomenon and how you can correct it.
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Is it Normal to Have One Bicep Bigger Than the Other?
It is entirely normal to have one arm bigger than the other. Asymmetry is a part of nature, whether we like it or not. You might have one eye that’s slightly bigger than the other or one leg that’s a little longer. In most cases, these differences are so subtle that they go undetected.
When it comes to muscle size, however, asymmetry is more noticeable. The main reason we notice asymmetry in muscle size is because we’re paying attention and tracking progress. However, there are preventable factors that could be influencing the variance and making it more pronounced as time goes on.
Why is One Bicep Bigger Than the Other?
There are a few reasons why one bicep might be larger than the other. The three common reasons include natural dominance, underlying injuries, and improper training form.
1. Dominant Hand
One of the leading causes of one bicep being larger than the other is in relation to your dominant hand. Throughout the day, you tend to use your dominant hand for more tasks than your non-dominant hand. Those daily tasks of carrying groceries or picking things up off the floor add up over time. The muscles in your dominant arm naturally get more exercise, causing the size difference.
2. Tendon Injury
Another reason you might be experiencing an imbalance in bicep size is an underlying injury. If you’ve had a muscular or tendon issue that hasn’t healed properly, it can impact how your bicep looks while flexing.
Tendon injuries aren’t uncommon and can happen during seemingly mundane exercises. Carrying something the wrong way can snap a bicep tendon with relative ease. Overtraining can also lead to a torn bicep tendon— another reason to prioritize rest and recovery.
When your bicep injury heals without corrective surgery, it will often reattach in the wrong place. This causes a bunched appearance, in which the muscle no longer extends from the shoulder to the elbow. As a result, the bicep looks significantly smaller than its counterpart.
3. Cheating the Movements
Working with proper form has significant impacts when training. You may be cheating the movements and allowing other body parts to pick up the slack without realizing it. When the muscles other than those you’re targeting take over the movement, it’s known as a compensation.
For example, as you start to get tired while doing barbell curls, your shoulders and traps might pick up the slack. While you’re able to complete the movement, it’s no longer having the desired effect.
The same effect applies if one arm is stronger than the other. Your right arm will make up for the left arm’s weakness and bear the weight. As a result, the strong arm will continue to get stronger, making the difference that much more noticeable.
What to Do If One Bicep Is Stronger Than the Other
If you notice a significant difference between your biceps, don’t panic. There are a few actions you can take to balance them out.
1. Know Your Compensations
First, it’s essential to get in tune with your body and become aware of your compensations. If you know that you cheat the movement and let your back take over during hammer curls, you can lean against the wall for balance. By doing so, you prevent your body from making swinging motions that transfer the movement from the biceps to the traps.
Use self-recorded videos or work with a coach to help identify imbalances and form improvement opportunities. It can also be helpful to train in front of a mirror during bicep exercises.
2. Use Unilateral Exercises
One of the most effective ways to even out biceps is to use unilateral exercises. In other words, work one arm at a time to isolate the biceps on each side. Swap out your barbell curls for dumbbell curls and use more single-arm bicep exercises.
By taking this approach, you’ll prevent your strong arm from picking up the slack of your weak arm. You can also tweak your training and do a few extra reps on the weak arm to help build strength and muscle mass over time.
3. Slow Down the Movement
Physics plays a subtle role in training. Curling 20lbs quickly can feel significantly different than curling 20lbs slowly. There are a few factors contributing to these differences, the most prevalent of which is momentum.
By slowing down the movement and adding torque, you can ensure the muscle is doing the work rather than momentum.
4. Use Resistance Bands
Finally, swapping out the weights for resistance bands can help you balance out your biceps. When you curl with a dumbbell, you may notice how much lighter the weight seems at the top of the movement. With a resistance band, the more you stretch it, the greater resistance.
At the top of the concentric part of the movement, you’ll experience more resistance with a band. Conversely, the eccentric movement will become easier. This is known as flipping or inverting the strength curve, and can help balance out your biceps.
Exercises When One Arm Bigger Than Other
1. Concentration Curls
Concentration curls remove momentum from the equation and prevent the movement from shifting to the shoulders. This isolation allows bodybuilders to focus on each arm separately and correct bicep imbalances.
How to:
- Sit on a bench with your feet firmly planted on the ground. Hold a dumbbell in a supinated hold, with your elbow resting on your inner thigh.
- Slowly curl the weight upward 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 back to starting position.
Take your time and move through this exercise slowly for best results.
2. Single-Arm Preacher Curl
Like concentration curls, preacher curls help prevent a shoulder shift when curling.
How to:
- 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.
- Slowly curl the weight up, keeping your upper arm fixed on the bench.
- When your forearm is perpendicular to the ceiling, pause and squeeze your bicep.
- Slowly lower back to starting position.
Single-arm preacher curls are a fantastic isolation exercise for targeting uneven biceps.
3. Incline Dumbbell Curl
Incline dumbbell curls are ideal for targeting the long head of the bicep. The increased range of motion sets this movement apart from other curl variations.
How to:
- Adjust your bench to a 45-degree angle. Grab 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 starting position and repeat on the other side.
Being slow and controlled is the key to success with this movement.
4. Lying Cable Curl
Laying down for cable curls may seem strange, but it’s an effective way to prevent motion transfer and effectively target the biceps. When performed unilaterally, this exercise is a must when you have one bicep bigger than the other.
How to:
- 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 and slowly lower back to starting position.
If you don’t have access to a cable machine, you can do this movement with a resistance band secured to a rack.
5. Single-Arm Reverse Cable Curl
The reverse cable curl is an often overlooked bicep exercise. Start with a light weight for this movement, which can be surprisingly deceptive.
How to:
- 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, squeeze, and slowly lower back to starting position.
Brace your core and keep your chest up for this workout. Consider resting your inactive hand on your abdomen as a reminder to stay firm and stable.
Conclusion
It’s completely normal to have one arm bigger than the other. However, it’s also reasonable to want to know how to balance out your biceps for an even flex.
First, identify any issues that may be causing the imbalance. Then, use unilateral exercises and proper form to isolate each arm and correct the problems. With time and effort, your biceps will even out.
