by Christian Thibaudeau
Why Deep Squats Aren't Always The Answer
Here's what you really need to know about the optimal squat depth.
Partial Squats: Perfectly Fine and Effective. Fight Me.
Tons of haters are throwing a tantrum on social media after reading that. But I’m not in the business of appeasing crybabies.
The thing is, I do full range squats most of the time. So do my athletes. My squats are ATG – ass to grass. I’ve squatted 600 pounds and front squatted 485 pounds ATG at a bodyweight of 195-204.
So talking about the benefits of partial or half squats doesn’t mean I hate deep squats. Now, let’s get on with it!
What’s a Partial Squat Exactly?
Let’s get something straight. If you’re thinking of a shallow knee flexion, then that’s not a partial squat. That’s a shallow knee flexion.
A half or partial squat still has a decent range of motion. To me, “half” is anywhere between 90 degrees and as low as it would be if the upper thighs were parallel to the floor.
Here’s an example of a member of the Canadian National Bobsleigh team. This is 250 kg for a double at a bodyweight of around 87 kg. This is what I call an acceptable partial squat.
Anything higher than 90 degrees is too shallow to be used as your main squatting exercise, but it can actually still be useful as an assistance exercise.
Hypertrophy, Strength, Performance
For Muscle Growth
The full squat is slightly better than half squats. That’s the conclusion I’ve come to after 29 years of training and 20 years of coaching, plus digging into scientific literature.
The majority of high-level bodybuilders don’t squat ATG, oftentimes because massive hamstrings and calves tend to restrict range of motion. Old-school bodybuilders from the 70s and 80s did, but parallel or a bit higher soon became the norm. Leg size has not decreased among bodybuilders. Quite the contrary.
For Strength
It’s close, but the half squat might be a bit better than ATG.
How about powerlifters? Or the Westside guys? The same strength coaches who are quick to attack lifters who don’t go ATG will also praise Louie Simmons and the Westside guys for the way they train.
This is ironic because the vast majority of their squats at Westside are at parallel or above. And they rely mostly on the box squat in training using a competition-height box (parallel) or a higher box (around 90 degrees of knee angle). Sometimes they use a low box, but it’s not a common exercise in the rotation.
On top of that, they also use chains or bands added to the bar on most squats. This further under-loads the bottom of the range of motion, essentially training the top quarter of the squat more than other portions.
Will any of the keyboard warriors attacking those who squat to parallel or 90 degrees go to Westside and tell these guys in person that they’re not really squatting?
I’m not telling you this to convince you to switch to half squats. I’m telling you this to show that those who decide to use heavy half squats (parallel up to 90 degrees knee angle, no higher) are not less “hardcore” or “serious” than those who squat ATG. Nor are they doing a useless and ineffective exercise. You can get quite strong and muscular with half squats.
For Athletic Performance
Again fairly similar, but if you use the half squat, you might need to add posterior chain work to be balanced, especially if you have shorter legs and a longer torso.
If you look at empirical evidence first, you’ll see that a lot of the strongest, fastest, and most powerful athletes never squat ATG. Look at track and field athletes. The half squat is much more prevalent among throwers than the full squat, and these athletes are amazingly strong and powerful.
Most elite sprinters also don’t go all the way down. One of the better examples is Ben Johnson who would squat with up to 600 pounds for 3 reps going down to 90 degrees or slightly lower, but never ATG. Turned out alright for him speed-wise.
Go to any college, NFL, NHL, or NBA gym and watch these guys train. You’ll find at least as many of them doing half squats as full squats.
What to Do Based On Your Goal
If you’re after maximal lower-body development, strength, and performance, you need a squat-pattern movement. But the difference between a parallel squat, a full squat, and an ATG squat won’t be significant.
It often boils down to which form of squatting you’re the most comfortable with. Normally, people with short legs and a long torso (especially if they have long tibias and short femurs) will be more comfortable with a full squat than with a parallel or 90-degree squat. When you have shorter legs, stopping in the half squat range puts more stress on the knee joint.
People with long legs and a short torso don’t have that issue. But for them, getting all the way down can be very hard to do mechanically.
The important thing is to squat. And squat at least down to 90 degrees. That’s the minimum acceptable depth for your main squat exercise, and ideally anywhere between thighs parallel and ATG.
You Already “Cheat” the Deadlift
Before we go on, let me ask you, is the Romanian deadlift an effective exercise?
Of course it is! Nobody will dispute that. In fact, a lot of people argue that it’s more effective than a regular deadlift in many regards.
Well, the Romanian deadlift is to the deadlift what the half squat is to the squat: a variation with a slightly reduced range of motion. And it’s no less effective or respected. So why not do the same with the half squat?
You should be training movement patterns, not focusing on which exercises are best. You have the following movement patterns to train:
- Vertical press
- Horizontal press
- Vertical pull
- Horizontal pull
- Hip hinge
- Squat
It’s more important to find a variation of each pattern that fits you (your levers, goals, and preferences) and train that variation hard, than it is to blindly follow people who tell you what exercises you must do.
Muscle Growth: What the Research Says
Many studies show greater muscle activation from partial squats (90 degrees) than full-range squats.
One study found that there was a greater activation of the glute maximus, biceps femoris, and erector spinae (butt, hams, and low back muscles) in the partial squat as opposed to a full squat (1).
During another study, researchers found that the vastus lateralis and vastus medialis (quad muscles) were most activated during a half squat (90 degrees) than a full squat (2).
Great! That means more hypertrophy, right? Not so fast. A greater muscle activity (measured by surface EMG) isn’t necessarily correlated with more growth.
Here’s why: Activating muscle fibers and having them create tension is only the first part of the equation. For maximum hypertrophy, the muscle fibers must lengthen/stretch while they’re producing a high amount of tension. That combo is what leads to muscle damage and mTOR activation.
If you lengthen/stretch a muscle fiber, but there’s not a lot of tension produced, you won’t trigger growth. If you produce a lot of tension, but you don’t lengthen the fibers, you won’t trigger a lot of growth either.
That’s why isometrics can be great for strength, but by itself it’s not as effective as lifting the weight when it comes to building size.
Why is that relevant? Because when you want to know if an exercise will be more effective, you need to look at whether the muscles being activated are also being lengthened/stretched while producing the tension.
In the partial squat, you might have more activation of the quads and glutes (measured via EMG) but because of the shorter range of motion, these two muscles won’t lengthen/stretch as much.
While muscle activation can be lower in a full-range squat, the fact that you’re stretching the muscle fibers more can lead to more hypertrophy, despite less activation.
That goes along with studies looking at hypertrophy instead of muscle activation. For example, researchers found significantly more hypertrophy in the glutes with full versus partial squats (around 6% versus 2%) (3). Gains in quads were similar in both types of squats (4.9% for full versus 4.6% for partial).
This reaffirms what I’ve observed in the trenches. And this is why I say partial squats are slightly less effective than the full squat when it comes to hypertrophy.
However, with a properly designed program that uses a hip hinge movement (preferably a Romanian deadlift) you won’t notice a difference in lower body development between a program using a parallel to 90-degree partial squat versus one using a full squat.
Strength and Performance
There are two big reasons for using partial squats:
- You can use more weight, which creates a greater overload in the trained range of motion.
- A proper partial squat trains the range of motion required by most sports and life activities. Rarely (except for baseball catchers) will you have to go lower than thigh parallel in a sport action.
Think about it. If you can create a greater overload in the trained range of motion by using less depth, and this shortened range covers all your needs when it comes to your sport, the benefits of partial squats are clear: you get stronger in the range of motion you need.
The downside? You’ll gain strength mostly in the trained joint angles. When you’re doing a partial squat, you won’t gain a lot of strength in the positions lower than those trained. However, since you go through the partial-squat range of motion when you’re doing a full squat, full squatting will also get you stronger in that partial range.
I mentioned earlier the various strength athletes who rely more on partial squats to increase their strength. The best example is throwers; the half squat is traditionally their go-to lower body exercise.
Peter Ingleton, a former thrower who now coaches athletes, reports that a thrower he knew (an Olympic medalist) said:
“The problem with using full squats during the last three months before competition is that it slows the throwers down. The quads should not wait for a full stretch or for help from the glutes or hams in order to fire. Never will this ever happen during a throw. I use the half squat, half front squat, step-up, full front squat, full back squat, lunge, and box squat… in that order of importance.”
Partial squats increase partial squatting strength more than full squats, and full squats will strengthen the full squat more than partial squats will. But full squats increase partial squats more than partial squats will increase full squat strength.
Arguments Against Partial Squats: Valid?
We see two major arguments from ATG purists. I used these arguments in the past too, but have changed my mind.
Argument One
Partial squats will create muscle imbalances that will lead to injuries.
If we look at the literature on muscle recruitment, we can see that this is simply not true. Look at the graph from Marchetti PH, et al (2016).
The potential imbalance mentioned is between the quads and hamstrings. But both the biceps femoris and semi-tendinosus have a similar activity in a 90-degree squat as in a full squat.
So, certainly, the imbalance can’t come from less strengthening of the hamstrings. The only valid point would be that partial squats are actually more effective for strengthening the quads than full squats. But as we saw earlier, the lower muscle activation in the full squat is compensated by a greater stretch leading to more hypertrophy.
The level of muscle activation is more relevant for strength development than hypertrophy in EMG research (in my opinion). But I can safely say that it’s unlikely that a proper partial squat would lead to more quad/ham imbalances than a full squat.
The only thing I could see is maybe a lesser strengthening of the glutes with partial squats. But very few programs only use the back squat for the lower body. If you include a hip hinge movement, the small difference in glute activity is likely irrelevant.
Now, if your goal is to use a minimalist approach and use the fewest exercises to get the job done, yeah, the full squat might be a bit more valuable than the partial squat. Maybe.
Argument Two
Orthopedically, the knee is most unstable at 90 degrees, so stopping and changing direction at that angle is more dangerous than doing a full squat.
Is this really true? Just think about it.
Most people naturally sprint from a 90-degree knee angle. The human body would be very inefficient if the natural locomotion pattern relied on the most dangerous mechanical position, wouldn’t it? Nobody would be able to play any sport involving sprinting or jumping if the 90-degree knee angle was that unstable and dangerous!
The body naturally activates the various muscles involved in the 90-degree joint angle. It’s capable of producing more force and active stability at that angle, making it no more unstable during dynamic movements as other knee angles.
Researchers from another study found that the vastus medialis, biceps femoris, tibialis anterior, and gastrocnemius can produce more force at a 90-degree angle than at a lower position. These are major knee stabilizers or muscles involved in maintaining your posture during the squatting motion.
I’m not saying you’ll be more stable at 90 degrees and thus should avoid back squatting, but that any disadvantage in passive stability at the 90-degree angle versus a lower position is compensated by a greater active stability.
The layman’s version? The 90-degree or parallel squat is not more dangerous or unstable as the full-range back squat.
The counterargument is that people can use too much weight on the partial squat making the injury risk greater. But that’s true with any exercise. Use too much weight compared to what you can lift with good form and your risk of injury will go up. The problem is not with the exercise, it’s with moronic weight selection.
The Take-Home Message
I’m a believer in the big basics. As such, the squat pattern is in pretty much every one of the programs I use with clients.
To be as effective as possible, a proper lower body program should involve a squat. But that doesn’t have to be a full, ATG back squat. It can be a back, front, Zercher, overhead, or split squat. It can be anywhere between ATG up to a 90-degree knee angle, depending on the person.
Any depth between ATG, thighs parallel, and 90 degrees will work fairly similarly for most people, especially if it’s included within a complete program – one which also contains a hip hinge exercise.
Everybody (who isn’t injured) should be able to do a proper full range squat. And for some specific cases, a full range squat might even be better (people with short legs/long torso, powerlifters lifting in the IPF with very strict depth standards, Olympic lifters, etc).
While “squatting high” may be a capital sin for some competitive powerlifters, if your goal is simply to get more muscular, stronger, and faster, it’s not as sinful as the exercise Nazis make it out to be. So stop looking down on someone who trains hard, but “only” squats to parallel or a bit higher.
References
References
- da Silva JJ et al. Muscle Activation Differs Between Partial and Full Back Squat Exercise With External Load Equated. J Strength Cond Res. 2017 Jun;31(6):1688-1693. PubMed.
- Marchetti PH et al. Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise. J Sports Med (Hindawi Publ Corp). 2016;2016:3846123. PubMed.
- Kubo K et al. Effects of Squat Training with Different Depths on Lower Limb Muscle Volumes. Eur J Appl Physiol. 2019 Sep;119(9):1933-1942. PubMed.
- Han D et al. The Effect of Knee Flexion Angles and Ground Conditions on the Muscle Activation of the Lower Extremity in the Squat Position. J Phys Ther Sci. 2017 Oct;29(10):1852-1855. PubMed.