It’s very rare to find someone that is truly ambidextrous. That means it’s very rare to find someone that doesn’t have some sort of muscular imbalance.
Muscular imbalances are when one muscle is stronger on one side of the body than the other. When this imbalance gets noticeable, that’s when people become self conscious about how they look. One such instance that is quite common is for people that just go through every day doing things with their dominant hand. This will cause that limb to be generally stronger, and in some cases larger than the opposing side.
I personally had this happen in high school when I was a waiter. I would always carry my serving tray in my left hand so I could grab the dishes with my right hand. This caused my right shoulder to become stronger and more dexterous. At the same time, it made my left bicep become larger and stronger because I would always use that to carry the majority of the weight when carrying food or drinks on the tray.
In high school this wasn’t a bid deal. But as I got older and retired from my athletic career of football and other sports, I started to become more aware of how I physically looked rather than how I performed in said sports. Naturally, my goal of being attractive to the opposite sex drove me to look into how to balance this out. It was at this time that I got my first taste of unilateral training.
Unilateral training is where you do an exercise with only one side of the body. A common example would be like single-arm dumbbell curls.
There are numerous benefits of unilateral training. The most prominent is going to be for rehabilitation, but there are many more than that. Just as with any other fitness tool, adding unilateral training to your physical fitness repertoire is extremely beneficial.
Now, studies have shown that one really cool thing that happens when you do unilateral training is that both sides of the body are effected, despite only using one side. Studies have proven this, and it is most prominent during the eccentric motion of the exercise. That is when you are lengthening the muscle. This means that when you are doing curls with your right arm, your brain will activate a cross-education and give the same benefits to the left arm, and vice versa. This does not mean that you only need to train one side of the body, it just means you get double the benefits.
Another incredible benefit, and what I utilized early on for physical appearance benefits, is that it evens out the muscles. The way this happens is by using the same weight for each side. To continue using the bicep curl example, if you were to be using a straight bar or EZ bar then one arm, usually the dominant one, will take a little more of the load simply because it is more natural. So, instead of both arms taking the load with 50% of the total weight, one arm could be taking 60% or even more. That gives one side more work than the other, creating the imbalance. When you isolate each limb with dumbbells, then each limb will be getting 100% of the load. There is no way for the other side to compensate for one side being weaker. This may lead for an individual to want to increase weight because one side is stronger than the other, but that completely defeats the purpose. Just keep the sets, reps, and weight the same for both sides. This will help catch up the lagging body part, and in the end, increase gains for both sides.
The third major benefit is the core engagement. A key when doing unilateral movements is keep your body rigid and not lean to the weighted side. The perfect example of this is a farmer walk. You hold a dumbbell in one hand and walk for an extended period of time, keeping your posture strong by engaging your core. This same idea is applied to single-arm shoulder press and bent over single-arm dumbbell row. The cool part about the core engagement is that it doesn’t target a specific muscle in your core (abs, back, or obliques) but it fully engages all of them together. Due to the larger muscle activation, that makes these lifts more functional.
There are numerous ways to incorporate unilateral work into your workouts. One such example is, if you still prefer the body part split, to use unilateral and bilateral work together. This is a common thing for physique competitors who isolate small muscles for the aesthetic benefit. It can also be used to catch up lagging body parts, as in my example earlier. Most commonly unilateral exercise is utilized for rehabilitation purposes because of being able to isolate a single injured muscle or joint.
Some examples of unilateral lifts are:
One-arm pull ups
One-arm push ups
Archer push ups and pull ups
Some of these movements require a high level of skill or strength, but they can typically be altered to be a bit easier if need be. At the same time, such movements may be increased by adding weight. All in all, there are many benefits that can come from unilateral training. It is especially useful for those that travel often because hotel gyms typically don’t offer a very good selection of training equipment, but they usually have dumbbells up to 50 pounds. There are also complete programs that rely solely on unilateral training such as those incorporated by Onnit and Jim Stoppani.