Unilateral training is when you are training using one limb or one side of the body compared to lifting weights with both limbs at same time called bilateral. Example of a bilateral exercise would be a squat, lifting with both legs, and a unilateral exercise would be a rear foot elevated split squat. Mike Boyle, a well known strength coach in MA likes to categorize his unilateral leg exercises. The first category is a static unsupported exercise, a great example is a single leg straight leg deadlift. The working leg is stationary and has no support from the other leg during the lift. The next category is a static supported exercise, a rear foot elevated split squat would fit this category. The working leg is stationary while the other leg is elevated on a bench giving support during the lift. The final category is dynamic and a few examples are your lunges and step ups. The working leg goes through phases where it has support from the other leg and then changes to no support during the lift. These categories can help give you a better picture on how unilateral training is not all a strict single leg exercise, but can also have support being in a split stance and both.
What is the purpose of training unilaterally? You might be thinking it would just be easier to just squat and not worry about the different single leg options. Let me ask you this, How often are you doing something that requires you being in a split stance position? The answer is every single day! Everytime you walk, take the stairs, or kneel down to grab something off the floor you are in a split stance and sometimes a single leg. Without training this movement, we can lose this ability, this skill to move around in a split stance. Taking the stairs can become difficult and exhausting, the ability to kneel down will seem impossible, and eventually the task of walking will become a challenge. Training your body to be strong on a single leg and in a split stance will help you overcome these challenges as we age. If you are young, it is hard to think about what your body is not able to do when it ages. I understand, I am in my 20’s and almost in my 30’s. Right now my body is strong and mobile, but if I do not create habits now for longevity then my body will break down in the future. Training in a unilateral stance will help keep my body strong and mobile as I age, and my goal in 30+ years is to be able to run, jump, and be mobile, without fear of injury. Think of unilateral training as eating your vegetables or a multivitamin, it is not exciting but necessary.
Here is a list of some of the benefits of unilateral training:
- Joint health & longevity
- foot/ankle/hip stability
- Rotary stability (core)
- Real life activities/sports
- Strength & Hypertrophy
- Addresses weaknesses/imbalances from limb-limb
- Exercise variety
As you can see a pretty long list with a variety of benefits. Naturally we are stronger unilaterally compared to bilateral, the body finds it confusing neurologically when lifting with 2 legs. If you take a unilateral leg squat variation and double it, it will be more than the bilateral squat itself. This is called a bilateral deficit. The nice thing about this is, you can load more on that single leg compared to the bilateral movement without the extra stress. Go back to the list above and you will see joint health, longevity, balance, and stability. When you load up heavy with a bilateral movement like the back squat, your joints are taking a large amount of stress, compared to the unilateral variations. If you are like me, I love back squats but can not do them all the time if I want healthy joints. If strength is your goal, and want to do a sport like powerlifting then you should absolutely get strong unilaterally. There is great carryover from unilateral strength to bilateral strength, but the opposite is not true. If all you did was bilateral movement, you will actually see that you are unbalanced, like a giraffe learning how to walk. Do not get me wrong, I think it is also important to train bilaterally. Squatting is a fundamental movement that should be trained, think about sitting on the toilet, you are squatting. I just want to make it very clear that you should not just be doing bilateral. You are missing out on gains if you do not train unilaterally.
Zoom out of your current time and think about the future, you would be setting your body up for failure if you never train unilaterally. This is especially true if you are an athlete. Studies are very clear that unilateral training can reduce your risk of injury. Let me be clear, not prevent injuries because that is impossible, but the risk of injury dramatically reduces with strength training unilaterally. This is also true for any individual since we do activities that require stability and balance. Train smart to feel and move better today and for your future.