- Part I — Isometrics
- Part II — Unilateral Training
- Part III — Plyometrics and Sprinting (Coming Soon)
In Part I of this series, we discussed a fantastic method for increasing (or in the very least, maintaining) strength in a creative fashion, by way of isometrics.
As noted in the previous post, there are several reasons why training in a “creative” manner can be valuable, including:
- Injury — an inability to load the body through traditional methods
- Age — a lack of desire/capability to train with significant loads
- Lack of Resources — for example, a pandemic shutting down gyms; travel is another time when this comes into play
- Change of Pace — after a while of heavy loading, alternative training cycles can be a great way to break up the monotony of consistent training methods
Today, we will discuss another effective method: unilateral training.
For a deeper dive, check out the e-book I wrote during the pandemic, How to Maintain While Training From Home: a guide for creating adaptation with limited resources
What is Unilateral Training?
There are many ways to categorize or ‘bucket’ strength-training exercises. One way to do so is to characterize them by the limbs used to complete them.
Bilateral quite literally means “two-sided”, while Unilateral means “one-sided.”
So, as you could imagine, bilateral exercises involve both sides of the body working together symmetrically to overcome a resistance, and unileratel exercises involve just one side of the body performing the action (or both sides working together, but asymmetrically). Some examples of each are found below:
Bilateral Exercises:
- Standard Squats and Deadlifts
- Push-Ups, Pull-Ups
- The Standard Bench Press or Barbell Row
Unilateral Exercises:
- Lunges and any Single-Leg variations of the Squat and Deadlift
- Single-Arm Dumbbell Press or Row
- Any Single-Arm or Single-Leg exercises
The Science of Strength Training: A Deeper Dive
In our last post, we discussed some of the science behind strength training. While we went into a good amount of depth then, a bit of a deeper dive might be helpful now:
The body produces force in order to overcome a resistance — be it simply standing up to overcome the pull of gravity, or standing up from a deep squat with a loaded barbell on our shoulders.
This force is generated by the skeletal muscles through muscular contractions. The larger the cross-sectional area of each muscle (i.e. the bigger the muscle is), the more force it has the capability of producing.
However, muscle size is not the only determinant of strength; the muscles are governed by the Central Nervous System (CNS), which includes the Brain, Brain Stem, and Spinal Cord. The CNS innervates (or connects and controls) the muscles through the nerves that run from our spine and to our limbs.
While a larger muscle has the capacity to produce more force than a smaller muscle, a stronger, more coordinated CNS also has a greater capacity to produce force, regardless of muscle size. This is why we often see feats of strength by lightweight individuals, such as featherweight weightlifters and powerlifters.
Together, the muscle and nervous system connect at neuromuscular junctions (or where nerves innervate the muscles, and each connection of nerve to muscle fiber bundle is termed the motor unit. At these neuromuscular junctions, electrical impulses are sent from the brain, through the brainstem and spinal cord, through the nerves, and into the muscle, causing the muscle fibers to contract and produce force.
So, to increase strength by way of improving the Central Nervous System, we are seeking to make this process of activating motor units faster, more effective, and more coordinated. There are many methods that can work to do this, but two of the most common are heavy strength training and ballistic training (or moving weight rapidly).
In the case of heavy strength training, the heavier the load is, the more motor units will be necessary to activate and produce the force required to overcome that load. Thus, by training heavy, we are training the neuromuscular system’s ability to activate as many motor units as possible.
The Value of Single-Limb Training
Single-limb — or unilateral — training begins to show its value by way of some simple math: it takes half as much load on the bar to get the same stimulus when using just one arm or leg. For example, If you can Bench Press 200 lbs for 5 reps, then in theory you only need 100 lbs for the same stimulus using one arm.
I say “in theory”, because realistically speaking, it is not that simple. Stability plays a large role in this as well, limiting the load we would need to get the same stimulus even more.
For example, when estimating the load needed on a 1-Arm DB Press from a Bench Press 1 Rep Max (1RM), I tend to use the following formula:
Load = (1RM*50%)*(80%) where the 50% cuts us down from two arms to one, and the 80% accounts for stability. Again, this is just an estimation — a ballpark number to start with
Regardless, it should makes sense that, whether it is an even 50% or some other percentage, we simply do not need as much load on the bar to challenge the muscles and nervous system when we are using one limb compared to two limbs.
So, why and when would this be an advantageous training method to deploy? While there are many reasons to incorporate unilateral training, we will highlight two in particular:
Back and Hip Issues
If you are an athlete who has any sort of back or hip issues, the advantage of using unilateral exercises is that it usually involves less overall loading of the body (since less load can be lifted by one limb when compared to two). In order words, when performing a Two-Legged Romanian Deadlift (RDL), you might need 200 lbs of load to challenge the muscles of the Posterior Chain (e.g. the Hamstrings, Glutes, Lower-Back). However, when performing a Single-Leg RDL, you might only use 95 lbs, loading the lower-back and body overall with nearly half the load.
Take a back-loaded squat as another example: the Back Squat might require you to use 300 lbs to get a significant stimulus on your legs. But, moving to a Barbell Split Squat might require only 135 lbs to do the same for each limb, but it ultimately loads the spine with less than half the amount of weight.
For those who struggle with back and/or hip pain, this reduction in load can turn strength-training from harmful to productive.
Lack of Resources
Whether you are traveling, stuck in the midst of pandemic-driven gym closures, or simply don’t have access to a full gym, a lack of resources can be a tough challenge to overcome.
However, one way to make the most of what you do have is to use the above math to your advantage: applying whatever load you have across one limb, as opposed to two, essentially doubles the exercise’s effectiveness; again, this is because less muscle mass will be available to produce force against the resistance, thus more motor units will be need to be recruited by the working muscles.
A Note on Transfer of Training
As discussed in other posts, those who are untrained will see rapid progress by incorporating just about any mode of resistance training to their regime. And, these strength gains can often make a quick impact on the bike.
However, for those that are more advanced, achieving a transfer of training from the weight room to the bike is often more challenging. What we know about transference is that joint angles and velocities matter when we are considering what and how to train in the weight room in order to see progress in our sport. Since cycling is a locomotor endeavor, each leg will work in an opposite fashion (just like running, walking, and crawling).
Thus, this essentially classifies cycling as a “unilateral sport”. This helps make the case even further for single-limb training, even when working with fully healthy, fully-resourced athletes.
Respectfully,
Ryan J. Faer
PEDAL PERFORMANCE 