Your Muscle Imbalance Is Holding You Back — Here's How to Fix It

You look in the mirror and think, "Hmm, weird. My left arm looks a little smaller than my right." Or you're always dreading Bulgarian split squats on one side over the other. Maybe you're an athlete who keeps dealing with the same injury, even after taking time to recover.

These could all be signs that your muscles aren't working as evenly as they should. From favoring one side during your workouts to compensating for an old injury, there are several reasons muscle imbalances develop — and several ways to address them.

What is Muscle Imbalance?

Muscle imbalance occurs when corresponding or opposing muscles — like left and right hamstrings or your bicep and tricep on the same arm — differ in size, strength, or flexibility.

While some degree of asymmetry is completely normal, pronounced muscular imbalances can disrupt your body's alignment, place extra stress on your joints, contribute to pain and injury, and ultimately limit your performance.

What Causes Muscle Imbalance?

Repetitive Movements

Athletes who throw, swing, catch, grab, kick, and push — and who favor one side of their body to do so — are often stronger on their dominant side. It makes sense: they practice and train using the same movements over and over. Similarly, people whose jobs require repetitive movements can develop muscle imbalances. In both cases, some muscles may become weaker than others because they aren't getting the same attention.

Injury Compensation

Your ankle hurts, so you adjust your gait to shift weight to the opposite foot. Some pain in your shoulder? You tweak your form to compensate for the injured area. These small adjustments may help you avoid pain in the moment, but over time, they can place uextra stress on other muscles and joints. As your body continues to compensate, some muscles become overworked while others become weaker, creating or worsening muscle imbalances.

Poor Posture and Movement Patterns

Hunched over your desk responding to emails, leaning to one side, or consistently standing with your weight shifted onto one leg may seem harmless, but these habits can affect how your muscles work together. Overtime, poor posture and inefficient movement patterns can cause some muscles to work harder than others, while others become underused.

For example, constantly slouching while you work at your computer can cause the muscles in the front of your shoulders and chest to become tight and overactive, while the muscles in your upper back and rear shoulders become weaker and less active. This type of muscle imbalance can affect your posture and shoulder mobility.

Imbalanced Exercise Routine

If you want harmony and symmetry between all of your muscles, you need to train all of your muscles. Doing the same exercises repeatedly — or focusing heavily on certain muscle groups while neglecting others — can create strength imbalances.

For example, regularly tackling squats and leg extensions while neglecting your hamstrings and glutes can cause the muscles on the front of your legs to become stronger than those at the back. This imbalance can affect how you move and put additional stress on your knees and hips.

How to Spot Muscle Imbalances

Muscle imbalances can be from one side of your body to the other, like comparing the strength in your left and right arms, or opposing muscle groups, like your chest and back muscles.

Here are some key areas to take note of if you're curious if you may have a muscle imbalance you'd like to address:

• Differences in strength, flexibility, and/or balance
• Noticeable difference in muscle size between the same muscles on each side of the body
• Movement limitations or a reduced range of motion in joints
• Persistent or recurring aches, strains, or stiffness
• Poor posture

Test for Imbalances

If you're unsure if you have a muscle imbalance, a visual assessment, movement assessment, and strength assessment can give you a better idea of where differences may exist in your arms, shoulders, back, chest, legs, glutes, and abs.

Visual assessment: Stand in front of a mirror and look for noticeable differences between your left and right side of your body. Are your shoulders or hips level? Does one side sit higher than the other? From here you can also look for differences in muscle size. You can also use a camera to capture your front and back side.

Movement assessment: Pay attention to how your body moves during exercises and everyday movements. Try movements such as squats, lunges, or overhead reaches and look for limitations in your range of motion or differences in balance from one side to the other. For example, one leg may feel less stable during a split squat or one shoulder might feel tighter when doing an overhead reach.

Strength assessment: Compare your strength on each side and between opposing muscle groups. Try unilateral exercises like single-arm curls, tricep kickbacks, flyes, rows, or single-leg exercises and compare the weight and number of reps you can perform on each side. You can also compare opposing muscle groups, like your biceps and triceps or quadriceps and hamstrings, to identify noticeable differences in strength.

How to Fix Muscle Imbalances

Muscle imbalances are common, and according to a review of 53 studies on inter-limb strength differences in the Journal of Sports Science & Medicine, there isn't a single percentage of strength difference that reliably predicts injury. However, targeted strength training and progressive overload (paired with getting enough protein each day) can help address imbalances by strengthening weaker muscles and ensuring opposing muscle groups are trained evenly.

Muscle Imbalance Exercises and Equipment

Strength train weaker muscles: Identify weaker or underused muscles and give them more attention through targeted strength exercises. If you're a rock climber who constantly uses your back for your sport, add push-ups and bench presses to your routine to add strength to your chest. Or, if you regularly carry loads with your dominant arm for work, add farmer's carries with your non-dominant arm in the gym. This can help bring weaker muscle groups up to the level of their stronger counterparts.

Unilateral exercises for muscle imbalance: Training one side of your body at a time — like lunges, single-leg RDLs, or single-arm presses — can help you identify and target muscle imbalances. Once targeted, start the exercise with your weaker side. Then, match the reps and weight with your stronger side.

Stretch tight muscles: Stretching can help improve flexibility in tight or shortened muscles, while strengthening can help address weaker muscles. However, studies have indicated that stretching without strength training won't correct muscle imbalances.

Use the right equipment: Beyond the right exercises, the right tools can help you isolate your weaker muscles. A cable machine like the REP ARES™ 2.0 or Arcadia™ Max functional trainer allow you to tackle unilateral work like single arm lat pulldowns, rows, presses, rows, and extensions with the D-handle attachment. And kettlebells and dumbbells — like the QuickDraw™ adjustable dumbbell — support unilateral work for both upper and lower body exercises.

Takeaway

Muscle imbalances are common, especially for athletes practicing repetitive movements, anyone who favors a certain side of their body during daily activity, or people who spend long hours sitting at a desk without good posture. 

Pay attention to differences in your strength, movement, flexibility, and muscle size, and use targeted exercises to address areas that may be weaker or underused. If an imbalance is causing pain or contributing to recurring injuries, consider working with a physical therapist to identify the underlying cause.

FAQs

What exercises are best for fixing muscle asymmetry?

Unilateral exercises are excellent for addressing and fixing muscle asymmetry. Start off by training your weaker side, then repeat with the same weight and rep range on the stronger side.

How can I correct muscle imbalances in my arms?

First, you'll want to identify which muscles are weaker in your arms. Then, you'll want to give those muscles some dedicated attention. Single-arm dumbbell curls, rows, tricep extensions, and shoulder press can help build strength in your weaker muscles.

How long does it take to fix muscle imbalance?

The amount of time it'll take to fix a muscle imbalance depends on the severity of the imbalance and frequency of training. For a moderate imbalance, two to three months of consistent effort can help improve symmetry and balance.