Strength in a Dominant Arm Vs. a Non-Dominant Arm

A common goal of bodybuilders and exercise enthusiasts is to sculpt a symmetrical physique that showcases balanced strength and muscle development. For athletes, symmetry can mean improved performance and a competitive edge. Making changes in your training regimen will help. But training alone may not be enough to offset imbalances in strength between dominant and non-dominant arms. You may need to make changes in your daily physical behaviors as well.

  1. Neurophysiology of "Handedness"

    • Because the right and left sides of the body are governed by opposing brain hemispheres, the neuropathways that influence movement of the dominant and non-dominant arms are distinct. According to a 2007 study published in "Experimental Brain Research," each hemisphere-limb system is "specialized for stabilizing different aspects of task performance." A 2011 Italian study in "Revista Andaluza de Medicina del Deporte" found a variance in muscle recruitment patterns between the dominant and non-dominant arms when performing an identical task. Essentially, the two sides are distinctly wired, and achieving ambidexterity in performance may require specific training that addresses those distinctions.

    Strength Imbalance

    • Despite the neurological differences between right and left, the musculature on both sides of the body is more or less identical, and the potential to influence the size and density of muscle fibers through strength training exists for both arms. One reason you often see an imbalance of strength between the two sides is that you are more apt to use your dominant arm to perform everyday tasks, and the cumulative effect results in greater strength in that arm. When training, you often select exercises that do not isolate the muscles of the right and left sides of the body independently of one another, resulting in a greater overall training load on the dominant arm.

    Modifying Behaviors

    • One way to overcome imbalanced strength is to make a conscious effort to modify your everyday behaviors. From taking out the trash to lifting your toddler, by deliberately focusing on using your non-dominant arm for everyday activities, you can gradually build strength and improve symmetry. The practice of conscious movement will also make you more aware of your body mechanics when performing common tasks, and it may reduce your risk of overuse injuries and postural imbalances.

    Training for Balance

    • The way you train can also affect an imbalance in strength. When performing exercises that use both arms simultaneously, you are likely to recruit the muscles of the dominant arm to a greater degree than those of the non-dominant. This can be avoided by using dumbbells rather than barbells, by using exercise equipment that provides bilateral load, and by doing bodyweight exercises that use one arm at a time. When loading and unloading weight plates, alternate the load-bearing arm between right and left so that both arms benefit from the workload.