A case for unilateral leg training

by Ryan Wagner

Training one leg at a time often gets a bad rap. Guys have a tendency to think that unilateral leg exercises like the split squat and pistol are just one small step away from a Zumba class.

And that’s a shame because training one leg at a time may end up being the most efficient way for most lifters to boost their strength.

What it is

Unilateral leg training is simply training one leg at a time. It doesn’t necessarily mean that you’ll always have one leg off the ground, but that the focus is only on one leg. A lunge is the standard example.

Now it’s easy to think that because we have two legs we are always using both of them. But let’s take a close look at a familiar example: Running. When you go out for a run are you using both legs? Well, yes and no. You’re certainly alternating between legs, but rarely will both legs be on the ground at the same time. This holds true for both a nice gentle running stride and a sprint.


Now let’s do something different. Imagine that you rotate your point of view 90 degrees such that you have a frontal or rear view. Let’s look at a couple compensations that your body makes.

Firstly, you’ll see that the hips are shifting to accommodate the weight distribution of one leg. If the hips didn’t do this then you would be off balance. Secondly, the spine must curve a little in order to accommodate the hips. If it didn’t then our shoulders and head wouldn’t be level anymore.

There are many other examples in sports when you won’t be on both feet. Cutting from side to side in football, ice hockey, even a golf swing. But the gist is that most athletic sports involve pushing off from a split stance. So why not train that way?

And here’s another interesting argument: The limiting factor for many people on bilateral movements is their back. In other words, when the weight gets too heavy, technique is going to break down from the upper body first. Think about it, how many times have you seen people coming up from the hole in a squat and their legs extend faster than their torso? It’s like their upper body couldn’t keep up with the lower body’s movement.

Now we are beginning to understand the logic behind unilateral training from a strength perspective. By training one leg at a time we can load up our legs with large weights without enduring excessive spinal compression. Generally, this will be less stressful on your body and you’ll also recover faster and be able to increase your training volume.

The exercise you need to know

Now I could spend time going through a long list of unilateral leg training exercises. I could discuss the lunge and you’d probably remember those days in P.E. class. Or, some of the less common variations like the side lunge or the one leg straight deadlift. But I’m not. Instead, I’m going to focus on what I think is the number one unilateral leg exercise for strength. An exercise that can provide benefits to both the novice and seasoned lifter – The Bulgarian split squat.

Among some lifters there is contention over whether this exercise actually hails from Bulgaria. Or if it’s actually called the Bulgarian split lunge. Sometimes it’s called RFESS (Rear foot elevated split squat). But T Nation readers and Mike Boyle followers aside, many people still remember this exercise for its most common name. Therefore, I’ll follow suit. So, let’s get started!

Will the Bulgarian split squat (BSS) improve a new lifter’s balance? Yup. What about flexibility in the hip? Of course. Sticking with dumbbells or kettlebells in the hands for most people will be just fine. But for the stronger athletes out there, try using a barbell so that you can load the weight higher. Now you can really load the legs, but spinal compression is far less than what it would be with a back squat.

Here’s the set up:

Set up for a Bulgarian split squat like you would a normal squat, but have a step or bench set up behind you. Unrack the bar like usual and take a step back. Lift your rear foot up on the step or bench and brace your core. Squat down to a certain depth and press back up. Complete your reps and switch sides. Be sure that your upper body remains upright throughout the movement and that either knee is dipping down the same distance.

And don’t look at your feet! It’s OK to gaze downward just a bit, but keep your head upright such that your spine and neck are in a neutral position.


For some people, elevating the rear foot is going to be uncomfortable due to the stretch in the hip flexors and quadriceps so it’s best to begin with a lower step or even to just have your rear foot on the floor – a lunge. Remember, just like all exercises, it’s important to be cognizant of your own progression and modify exercises as needed.

Rather than reinvent the wheel, here’s a simple how-to video from Men’s Health:

And here’s a more in depth – although well worth the time if you’re a serious fitness enthusiast – video on the same movement including some progression keys from Boyle.

Backing it all up

Don’t believe me? Are you shaking your head thinking, “Well, the split squat is cute and all, but it’s not going to find it’s way into my program for any length of time.”

Like so many things in the fitness world, there is rarely a definitive answer to a question. More often we hear some variation on ‘it depends.’ And everyone’s body is different. That’s the reason I don’t prescribe workout programs on this blog. Rather, I offer up concepts and methods for you to consider and leave the final call up to you.

That being said, I provide two interesting arguments below. You make the call. Is there any hard evidence presented in the cases below? Let me know in the comments or shoot me an email.

Captive hockey players

The first is a non-clinical study performed by respected strength coach Mike Boyle out of Massachusetts. For those of you that don’t know, Boyle is one of the most highly sought after strength coaches in the United States and has trained a wide range of athletes over the years. Recently, he decided to take a close look at how he was training a group of hockey players. He put his athletes through a six week program of rear foot elevated split squats in place of traditional back or front squats.

Then after six weeks he tested the athletes for their original 1 RM on the back squat. He took this back squat max, reduced it by 50%, and asked the guys to Bulgarian split squat that poundage as many times as they could. What he found is that his athletes lifted 50% of their original back squat 1 RM for 14 times after Boyle’s program(1)!

Although this was not a scientific study, his findings suggest that by focusing on one leg at a time, he is able to load the leg higher by bypassing the back. If the back is indeed the weak link when is comes to a back squat then it makes good sense to give your back a break by reducing poundage. But by training unilaterally you can still put each leg through a workout that even your ancestors will feel.

A tale of two force plates

Alternatively, a recent clinical study set out to determine how weight distribution plays a role in technique of bilateral movements, i.e. the squat(3). You see, no one has perfect weight distribution. Our organs are set to different sides of our body and are far from symmetrical themselves. Add to the mix each of our unique injury histories and you have a body that compensates in all sorts of little subtle ways. Next time you’re standing in line at the coffee shop take note of our posture. Are you biasing on one leg? Probably. But is this a bad thing?

The study set out to look at how the subjects’ squat was impacted by each of their muscular biases. You can read a nice overview of the study here, but here’s what they found: Weight distributions persisted even during a bilateral movement. And remember, the squat is traditionally billed as an exercise to correct these asymmetries. Instead, your body is doing what it does best and working as one great big integrated unit to get the job done.

Path of least resistance is king. Instead of lifting equally through each leg, the lifters made very small technique modifications such as angling the bar to one side to help distribute the load per their musculature.

Now, one clinical study is far from a definitive answer on the topic and it would be unwise to draw such a conclusion. However, this is interesting, isn’t it? That just because both feet are on the ground the body may not always be using them equally.

Synergy with squats

But what about a good strong, healthy squat? After all, squatting is a fundamental human movement. We squat down when we pick something up, when we go to the bathroom and when there is no chair around to take a rest. And even though many of our activities may begin from a split squat stance, there are still times when we want our legs to work in unison.


Am I proposing we all give up on our squats for good? Of course not. To build the sort of leg strength that can literally lift cars off the ground you need to squat heavy and squat often. The back squat and front squat are staples of a serious strength training regime. However, most guys and gals in the gym aren’t setting out to back squat twice their body weight and they certainly aren’t measuring the circumference of their thighs once a week!

Instead, most dudes just want stronger looking legs. That’s all. And many girls are looking to shape a sexy butt.

So will squatting get them there? Of course it will. But they’ll need great hip mobility and thoracic movement to squat with good technique and do so safely. The average decontidioned American could definitely use some work in these areas.

But let’s be very clear on one thing: Squatting is one of the five fundamental human movements. Squatting heavy with a barbell is not for everyone, but at the very least, healthy and uninjured people would be wise to consider body weight squats to some extent in their program.

Here are some other alternatives to consider:

  • Goblet squats
  • Kettlebell squats
  • Med ball squats

So why is it that single leg training isn’t more popular? We partly have strength sports to blame – bodybuilding, powerlifting. But team sports and popular individual sports like triathlons and running are geared toward the athlete. Athletes need movement. They need speed. Agility. All of which rarely involves pressing off of both feet at the same time. So why train that way exclusively?

Options like the Bulgarian split squat above are more spine friendly and show promise as a serious strength builder. The split squat takes balance and it takes proprioception. And when you start lifting heavy it demands confidence. It may even teach you something new about the level of discomfort you can take.

And here’s another reason you may not have seen the split squat in the gym recently – and this won’t come as any surprise 😉 – but guys don’t really like taking weights off of the bar. And that’s exactly what you’ll have to do if you graduate to the Bulgarian split squat with a barbell. It won’t look as impressive without the big weight plates over your back, but like so many things in the gym, it’s important to leave your ego at the door.

So what will work best for you? Well, you’ll have to experiment. Perhaps you’ll want to try increasing your unilateral leg training and mix in some squats cycles from time to time. You may just be surprised at how your balance and flexibility improve.

What other unilateral exercises have worked for you?


Recommended further reading

T Nation: 5 superior single leg exercises

Ben Bruno: Single leg squat experiment


(1) http://www.performbetter.com/webapp/wcs/stores/servlet/PBOnePieceView?storeId=10151&languageId=-1&pagename=372

(2) http://www.danogborn.com/strong-science/strong-science-2/#.UvMd5xCwLfw

(3) Sato, K & Heise, GD (2012). Journal of strength and conditioning research. 26(2), 342–349

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