The Value of Unilateral Exercise

Exercise selection is a fascinating topic. We choose exercises based on our desired outcomes and with regard to what works best for our unique bodies. And we determine how we perform those movements pertaining to body position, load, range, and tempo. 

Last week we talked about training for movement competency. We acknowledged the value of an exercise for strength, hypertrophy, power, and endurance. But we emphasized the use of exercise in the simple pursuit of moving better. Training to make our motion poetic, graceful, and artistic. Pleasant to the onlooker. Highly efficient and economical. Stuff like that.

This week we’re going to explore the value of unilateral exercise. Performing resistance and mobility exercises on one side of the body at a time. We’ll examine some of the parameters and indications related to this type of training. But first, let’s give consideration to the more traditional bilateral exercises.

Bilateral exercises are the standard in athletics and fitness. For good reason. Most are relatively easy to learn and perform. They are highly effective in activating a lot of muscles in basic movement patterns. Bilateral movements are the best way to put heavy loads into the body and in most cases to safely produce maximum force. But as with many things, there are a few cons to go along with the pros.

Bilateral movements are generally symmetrical, “squared-up,” and performed in the sagittal plane. This is moving up/down and forward/backward. Think of viewing someone from the side as he performs squats, traditional deadlifts, presses, and rows. The term functional comes to mind here, and some folks like to debate the relative functionality of any movement. Bilateral movements are definitely functional because we use our bodies in saggital orientations throughout the day. But, we also move many ways which are not so squared up.

From a biomechanics perspective, all motion is triplanar, in that it combines movement in not only the sagittal but also the frontal and transverse planes, about x, y, and z axes. No matter what motion we are producing, our limbs move sideways and rotate along with their sagittal translations. Our bodies are designed to wind and unwind in helical fashion. This occurs in varying degrees based on the movement task at hand and in accordance with any constraints present in the system. 

However, if we attempt to force the body to move in only one plane, using sagittal plane bilateral exercises in this example, we limit (but do not completely eliminate) the concomitant motion which occurs in the other two planes. This motion has to go somewhere. If we fix or lock the hands or feet in these bilateral positions, we can make the limb move mainly in one plane. But the joint has to take up some of the force in the form of what is known as accessory motion and interarticular, or cartilaginous, shear. Most of the time this is no problem because of the magic of arthrokinematic spin, roll, and glide at the joint surface. However, if something is even a little “off” during high loads or multiple repetitions, there is a resultant wear and tear phenomenon in the joint.

Movement can be suboptimal for any number of reasons ranging from congenital conditions, substitution patterns secondary to prior injury, fatigue, poor technique, distraction, etc. But a unique adaptation occurs if an athlete does only bilateral training (heavy enough and consistently enough). She usually develops a compressive state which reduces movement variability. In other words, you can get so good at doing bilateral movements that you stiffen a bit and lose that little bit of triplanar motion that allows for fluid movement and which keeps the joints healthy. In this case the joints don’t have any play,  and subsequently don’t use all (or most) of their required surface area. Areas of high pressure and grinding result, which is the precursor to osteoarthritic joint degeneration. 

The aforementioned situation can be fairly easily avoided by simply doing some unilateral training on occasion. Bilateral exercises are great and they probably should make up the majority of our exercises, most of the time. But doing unilateral movements can help to restore our much needed movement variability. So in this sense unilateral exercises, performed on an intermittent basis, can be a preventative solution to a problem we don’t have to acquire. Prophylactic physiotherapy.

But unilateral exercises are way more than just options to break up monotony or keep us out of orthopedic trouble. They allow us to be truly triplanar in motion and they have the potential for a very high degree of functionality. Unilateral exercises promote multidirectional stability and movement competency because they often utilize asymmetrical positions and stances. They allow the body to wind and unwind in all 3 planes.

It’s worth noting that the concept of planes, or three-dimensional space, is merely a construct developed by brilliant humans to make sense of spatial orientation. There really are no distinct lines demarcating one plane from another. As the body moves, the axis of rotation of every plane shifts automatically and dynamically adjusts to the situation. 

We also have many debates around movement itself. The CNS drives the system. Whether you believe that motion is a result of fluid shifts secondary to pressure differentials or the result of linkages, levers, pulleys, and fulcrums…it matters not for the purpose of this discussion. 

Coming back around to exercise selection, we want movements that yield the highest return on investment. Bang for your training buck. This is where unilateral exercises (UE’s) really shine. Here are some distinct benefits of unilateral exercises:

• They allow you to isolate a joint, muscle, or movement path.
• UE’s can help you to expose weakness, restriction, or motor control patterns, and thus improve them.
• They can, in specific instances, facilitate full-body integration.
• UE’s encourage the trainee to find the ideal movement path for his/her unique anatomy and consequently “put their signature on the movement.”
• They are much easier on the joints because they foster the helical, triplanar motion which decreases joint shear.
• UE’s are arguably the most functional, or natural, movements we can employ in a workout.

While there are many options for unilateral exercises, I’m going to describe a handful that we utilize often in our training community. This includes online coaching clients and Training Tribe members of all ages and abilities.  With each of these exercises, you’ll do all reps on one side before starting a set on the other. Set and rep schemes are up to you.

Unilateral Pulldown: Use an overhead pulldown machine with a handle or attach a band/tube to a pullup bar. This exercise can be performed in half-kneeling (one knee down on padding) or from a deep sitting position (supported squat on two yoga bricks for example). Quarter away from the anchor so that you are facing somewhat sideways (doesn’t matter how much…experiment) as you start the pull. Wind down and inward (toward midline) as you complete each rep. Explore kneeling on same side versus opposite side leg (relative to the hand that is working) and/or depth of sitting if you prefer that option. Let the trunk find its most comfortable position and path as you train. This is a very primal pattern known as brachiation.

Staggered Stance KB Overhead Press: Assume a staggered stance that is roughly halfway between the feet being side to side and forward-back. Put a KB in a rack position at your shoulder over the “back” foot. Sink down and wind backward at the start. Rise up and wind toward the front foot, finishing with an overhead press. Find the amount of vertical descent and rotation that feels most powerful.

Low Anchor Reaching Row: Use a similar staggered stance with left foot forward and handle in right hand. Set pulley (or connect band) at roughly mid-shin height. Back up until you are in a reaching, stretched position with tension on the cable or band to begin the pull. Smoothly rise up and rotate backwards (toward back foot) as you fully retract the shoulder girdle.

Punch Press: Set the anchor just below chest level, facing away from it. Press forward just like you’re throwing a punch, loading toward the front foot and leaning/twisting as you fully extend. This will come very naturally and needs no further explanation.

Ipsilaterally Loaded Kickstand RDL: Hold a DB or KB at your side, on the same side as the front foot. Place the rear foot behind you on a low box of 6-12 inches. Use a moderate stagger such that the rear foot is 15-18” back. Use a stiff front leg and a good hinge pattern to lower and rise. Try to keep some pressure on your outside heel as you perform the lift, especially at the top of the range of motion. This increases posterior chain activation.

Contralaterally Loaded Forward Stepping Lunge: Stand with feet parallel holding a KB or DB on the opposite side of the foot that will be stepping forward. Take a long step out, landing on your outside heel but letting the weight distribution move forward and inward on your foot until you feel most of the pressure on your 1st metatarsal head (inside ball behind big toe). Allow your knee to naturally drift forward and slightly inward. Then press up and step back to the starting position. This is mainly a forward-backward movement which mimics locomotive patterns. But you’ll be able to feel that lateral shift and rotation with each rep, especially if you concentrate on the foot pressures and knee translations.

Suitcase Carry: Grab a heavy KB, DB, or fill an actual suitcase full of books. Walk tall until you need to switch hands. Repeat several times.

That short list represents just a few of the many options for unilateral training. Here are several things to think about as you perform the exercises.

• Try to move your thinking away from a muscle-centric view. These exercises are more about using a number of muscles in harmony to produce effective movement. As opposed to a bodybuilding or hypertrophy focus, we’re going for highly functional movement.
• Similar to the last point, avoid trying to capture only one pattern, such as a horizontal press. Instead, utilize a composite output which blends aspects of multiple patterns throughout the body.
• Explore how weight shifting and hip/trunk rotation allows you to adjust force and optimize the “groove” of your motion.
• As long as your overall conditioning is relatively high, you won’t need much rest between sets (except for the heaviest of them). That’s because one side is resting while the other is working. In this manner, unilateral training takes about the same amount of time as bilateral training (which mandates longer dedicated rest periods between multiple sets of the same exercise). 
• Pay attention to how your joints feel as you do each rep. You can micro-adjust body position and the contribution of adjacent body parts to, in most cases, avoid discomfort.

Going out on a bit of a limb here, you could say that the exercises depicted previously, make a pretty damn good longevity-based workout for a Lifetime Athlete. Hit it once a week in place of a more traditional lifting session and try one of the following options.

Unilateral exercises are awesome. They can help to balance out your body as they restore movement variability. They can be a refreshing change of pace. They are easy on your joints. And they are fun. I hope you’ll consider adding some unilateral training into your conditioning program. The sky’s the limit!