Since strength training is inherently linked to our bodies, there are a lot of medical terms and fancy terms involved with strength training. There are two different types of strength training exercises, unilateral or one-sided and bilateral or two-sided. Let’s break down the difference between unilateral and bilateral strength training and what you should know about both types of training.

Why Care About Strength Training?

Example of a Unilateral Exercise - Single Arm Row

Aside from the obvious, “you get strong by training your muscles” understanding the complexities of strength training helps you create a balanced, impactful workout routine. This all starts with joint stability. Without joint stability, it doesn’t matter how strong you are, you leave yourself open to getting seriously injured.

So how do you create a strength workout routine that promotes joint stability? You’ll want a balanced workout routine that incorporates both unilateral and bilateral strength-building exercises.

Unilateral vs Bilateral Movement

Unilateral movement refers to movements that occur on one side of the body or movement that occurs with the body in an unstable position. Typically one arm or leg is moving at a time. Walking and picking up items off the floor with one hand are daily activity examples.

Bilateral movement refers to movements that occur with both sides of the body acting in tandem. For example, pushing a heavy box across a floor with two hands, or picking up a laundry basket.

What is Unilateral Strength Training?

Unilateral strength training refers to working out one side of the body at a time. For example, doing a one-armed curl. Unilateral strength training enables you to focus on one side of the body and promotes equal strength across the body. Since you’re working off-balance, your entire body works harder towards stabilization. The result is strong, healthy joints that aid in injury prevention.

Most physical therapy or PT is unilateral strength training, at least in the beginning. This type of training is an essential part of any strength training workout, especially if you’ve ever been injured. When you’re injured, your connection to your joints never fully recovers. However, you can gain 95 percent of your effective joint stability back if you maintain a steady unilateral workout.

Benefits of adding Unilateral Exercises

Equal strength promoted through the body
The non-working side is still stimulated for muscle growth during the exercise
Your balance and proprioception improve

What is Bilateral Strength Training?

Bilateral strength training refers to workout out both sides of your body at the same time. An example would be a leg press where you use a machine to press both of your legs at the same time. You’re able to lift more weight this way, which helps to build max strength.

However, bilateral training doesn’t train your body evenly. When you utilize both sides of your body for an exercise, one side inevitably works harder than the other. This effect is especially compounded if you’ve had an injury on one side of your body. The result is unequal strength building and de-stabilized joints in the absence of unilateral training. Bilateral training is important, however, for increasing your max strength.

Benefits of Bilateral Exercises

Typically, more resistance can be added which can help increase maximum strength
In real life, we don’t often move in a balanced way - training with bilateral movements can help align the body
Bilateral movement exercises can often be trained with strength machines, which have their own benefits, especially for hypermobile people.

Which Type of Strength Training Should I Do?

The answer is both. First, you want to build up your joint stabilization before you work on your max strength. Otherwise, you’re opening yourself up to a potential injury and no one wants to get hurt. Unilateral training puts the same amount of weight on both sides, equally (since you work one side at a time. The result forces your joints to stabilize in an equal fashion.

If you rely heavily on weight machines, make sure you dedicate at least one day to free weights or unilateral exercises with weight machines. Read why, here.

Think about periodization or utilizing periods of time to build strength in a sustainable, healthy way. One way to do this is to spend four to six weeks focusing on stabilizing with unilateral training and then four to six weeks building strength with bilateral training. The result is a balanced strength building over time.

What Is the Best Type of Strength Training for Injuries?

If you’ve been injured, either currently or in the past, the game changes a bit. It’s important to build back that important joint stability in a healthy, sustainable way. Even if you aren’t seeing a physical therapist anymore, dedicate at least one day to physical therapy exercises in order to upkeep joint stability. Essentially you’re encouraging the re-build of neurological connections between your joints, brain, and muscles. This, in turn, creates more joint stabilization over time.

Continuing with physical therapy is especially important if you obtained a stress injury due to a recurring problem or you underwent surgery. Continuing to engage with physical therapy encourages continued maintenance of your joints and the tiny muscle groups that support them.

What is the Best Type of Strength Training for Hypermobility/Ehlers-Danlos Syndrome?

If you are hypermobile, you will most likely benefit from using both unilateral and bilateral training during the same week or even the same training session. You may want to shorten your periodization cycles down to 2-4 weeks as opposed to 4 to 6. Unilateral training is very important for developing even strength around the joints and base stability, but bilateral training can be used to obtain a base level of muscle strength and endurance that is needed to safely perform some unilateral exercises.

Overall, the key to maintaining a healthy workout routine is to seek a balance for both unilateral and bilateral workouts. To learn how to create a balanced workout routine, and ensure you’re doing exercises in a healthy, safe way, hire a personal trainer.

Unilateral Vs Bilateral Training and Why You Should Give a Damn