Recently in Reformer Pilates classes (where we are performing unilateral exercises) lots of students have commented that they have noticed they are stronger or weaker on one side of the body compared to the other. They are quite surprised to learn for the first time that they have an imbalance in their body. Mind/body style classes particularly Reformer Pilates are great at bringing imbalances to our awareness.

Generally a Pilates (mat/reformer) or yoga class has a mix of bilateral and unilateral movement. Bilateral movement shares the resistance between two limbs eg. Chair Pose (uttkatasana) Squat, Knee Hovers or Bridge Pose (Setu Bandhasana). Unilateral movement places stress on only one limb eg. Lunge (Anjaneyasana) or Aeroplane Pose (Dekasana). Which is better unilateral or bilateral? Well, they both have their benefits which is why it is a good idea to incorporate both in a class.

Sometimes we can find that our bodies have an imbalance and that can be due to our unique bodies, past injuries or because we have a naturally dominant side.

Bilateral exercises are inherently more stable than unilateral exercises because they allow you to distribute weight evenly over both sides of your body. However, when we move bilaterally our stronger side can compensate by taking on more of the load than the weaker side therefore adding to our imbalance. Some other examples of bilateral movement may be: Planks, Downward Facing Dog, Bow Pose (Rocking in Pilates), Bridge Pose, Boat Pose (Teaser).

The primary benefit of unilateral exercises is the ability to train both sides of the body equally. It prevents overusing, overtraining or compensating with the dominant side, which helps to isolate and correct muscle imbalances which can aid in injury prevention and rehabilitation. Some examples of unilateral asanas would be Bird Dog, Side Plank/Bend, Warrior Poses, 1 legged Bridge Pose, Mermaid.

So, by practicing Unilateral exercises that challenge one side of your body at a time you prevent muscle imbalances from developing because each side is forced to bear the load independently. However, sometimes after an injury or imbalance we need the stability of bilateral exercise until we build up strength to eventually work unilaterally so a health professional can best advise you in regard to this.

There are other great benefits to using more unilateral poses in your practice; one of these is that core strength is improved because we automatically recruit the muscles of the core. When we work unilaterally, muscles also have to coordinate with the nervous system to control movement and maintain balance. So, we also see neurological benefits as the brain builds new nerve junctions.

Unilateral exercises help you maintain or gain strength in an injured arm or leg thanks to the cross-education phenomenon, a bizarre neurophysiological process where an increase in strength in one limb helps to increase the strength of the other, even when you don’t train it. 
For example, if your left biceps is injured, training your right biceps should help maintain or increase strength in the left arm without training it directly.
In one study, participants who only trained one arm increased their biceps curl one-rep max by 9% in the arm they trained and 7% in the arm they didn’t. In other words, by training their right arm, their left arm became 80% as strong, despite not doing any work. [1]

• Next time you practice Unilateral exercises be mindful and take time in the practice to notice in if one side is able to hold with ease and the other starts to get the shakes. Maybe one side can easily do a certain amount of repetitions but the other side really struggles. This might help indicate which side is weaker.
• Once it has been established (if it can be) which side is weaker and stronger, try in your own time to start the practice on the weaker side first, notice the exact amount of breaths or repetitions that you are able to hold or perform and don’t allow yourself to hold longer on the more dominant side.
• If you want to work on strengthening the weaker side of the body and you are 100% aware of which side that is, you could start to hold a strengthening pose for a little longer or repeat half the repetitions on that side. A specialist (chiropractor, physiotherapist, osteopath) may be able to tell you which side is your dominant side.
• It is not just the left and right side of the body that can become imbalanced, make sure that the front and back of the body are also worked in unison. Some new students think working the core means lots of abdominal exercises and end up with a tight front body and an over stretched and weak back body. So, remember to balance any abdominal exercises with backbends and vise versa!
• Once you have worked on finding a balance with your breath and practice, pause in a reflective supine pose like Sleeping Butterfly (Supta Badha Konasana) or step off your mat and notice what may be balanced or imbalanced in your life. How is the work/home balance going? Are your relationships balanced at present; are you speaking your truth, walking your talk? What needs changing and how can you go about it?

1. Unilateral vs. Bilateral Exercises: Which Is Better for Muscle Building and Performance? by Mike Matthews.

Article: Martine Ford