If you want bigger legs, how deep should you squat? Is a parallel squat good enough? Or is arse-to-ankles the only way to go?
Few questions divide opinion more than “how deep should you squat?”
On the one hand, you have people saying that a parallel squat, or slightly above, is good enough.
What this means is that the femur, the large bone in your thigh that runs from your hip to your knee, should end up roughly parallel to the floor.
Others will tell you to squat arse-to-ankles, which basically means as low as you can get.
If you can’t get that low then there is some kind of “dysfunction” that needs addressing. Most people had this range of motion as a child, they point out, and it’s possible to recover this with practice.
Full vs Parallel Squat: How Deep Should You Go?
Squat depth is important, but so is good form. With very few exceptions, you should squat no lower than the point where you lose the arch in your lower back.
For some, this will be a parallel squat or slightly below. For others, this will mean stopping slightly above parallel. Only a very small number of people can go arse-to-ankles without compromising their technique.
If you blindly follow the advice to squat “arse-to-ankles” (or even to parallel) while ignoring what’s happening to your lower back, the potential for some kind of disc injury is greatly increased.
If your spine repeatedly flattens out and loses its natural curvature with a heavy barbell across your shoulders, you’re doing more than just inviting trouble. You’re rolling out the red carpet and asking him to move in.
Neutral spine isn’t a single position that your back never deviates from. Think of it more like a neutral zone, or a range that your spine can move within while still posing a low risk of tissue damage.
In this video, Professor Stuart McGill, an expert in spine function and injury prevention at the University of Waterloo in Canada, explains exactly why losing neutral spine during the squat is a bad idea.
Your ability to maintain a neutral spine during the squat depends on a number of factors. These include:
- The strength of the muscles around the hip
- The flexibility of the hip and knee joint
- The relative lengths of your torso and thighs.
If you have relatively long thighs, for example, you’ll have to shift your weight back by leaning forward as you squat. Combine this with a lack of flexibility in the hip area, and you’ll find it very difficult to get below parallel without losing the arch in your lower back.
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Bret Contreras explains more about how anatomical differences from person to person affect squat depth in the video below.
“If squatting makes your joints cranky, consider setting your depth to a point that allows you to load up and still feel great afterwards,” explains Geoff Girvitz of Bang Fitness.
“Sometimes the difference of a single inch of depth can be huge in terms of impact to hip or low-back health.”
Squatting to Parallel, Or Even Slightly Above, Is Good Enough
Some people will tell you that if it’s not arse-to-ankles, the squat won’t make much of a contribution to gains in size and strength because it wasn’t done through a full range of motion.
Many of these same people will then go on to recommend the deadlift as one of the best overall mass building exercises for the entire body. That’s despite the fact there is not one muscle group that is taken through a full range of motion during the deadlift.
Unless you’re training to improve your performance in a sport where you need to be strong in a deep squat position, don’t worry if you can’t get below parallel.
Dr Rafael Escamilla, a Professor in the Department of Physical Therapy at California State University, reviewed a total 70 studies on the subject of knee biomechanics during the squat .
He found that squatting roughly to parallel is enough to achieve very high levels of muscular activity in the quadriceps, which is going to make your legs bigger and stronger.
Parallel Squats and Muscle Activity
Research that compares full-depth with parallel squats shows very little difference in muscle activity between the two.
Researchers from Edge Hill University, for example, looked at muscle activity during the partial, parallel and full-depth squat using relative 5-rep-max loads .
In other words, subjects lifted the most weight during the partial squat, and the least during the full squat.
Muscle activity in the hips and thighs was greater during the full-depth and parallel squat compared to the partial squat. However, the differences between the full-depth and parallel squat were, to quote the study authors, “negligible.”
There is research to show that muscle activation of the glutes is maximized during full squats . However, the main weakness with this study is the fact that subjects used the same weight for both the full and parallel squat.
Why is that a problem?
Most people can lift more weight in a parallel squat than they can in a full-depth squat. And muscle recruitment is highly dependent on the amount of weight you’re lifting. Squatting with a heavier weight will call into action more muscle fibers than squatting with a lighter weight.
Follow-up studies that take into account the fact that you can lift more weight in a parallel versus a full squat show that the glutes are just as active with parallel squats as they are with full-depth squats .
Muscle Growth with Full vs Above Parallel Squats
While it’s always interesting to look at how this or that exercise affects different muscles, short-term differences in muscle activity don’t always translate to long-term differences in muscle growth.
That is, you can’t always rely on EMG to tell you which exercise will lead to more muscle being gained.
For that, we need research to look directly at long-term changes in muscle mass, rather than short-term differences in muscle activation.
One such study, published in the European Journal of Applied Physiology by a team of Japanese researchers, looked at the rate of growth in various muscles after 10 weeks of squatting .
- Group one did above parallel squats, defined as 90 degrees of knee flexion.
- Group two did full squats, defined as 140 degrees of knee flexion.
The image below, which comes from this study, give you an idea what those knee flexion angles look like:
A = Above parallel squat (roughly 95 degrees knee flexion)
B = Parallel squat (roughly 125 degrees of knee flexion)
C = Below parallel squat (roughly 140 degrees of knee flexion)
So, what happened? Which group gained the most muscle?
MRI scans taken at the start and end of the study show no significant difference in the rate of quad growth between the two groups.
Whether the men squatted to 90 degrees of knee flexion, or arse-to-ankles, the increase in quad size was virtually identical.
However, the full squat did lead to a faster rate of muscle growth in both gluteus maximus and the adductors.
- Full Squat + 6.7%
- Above Parallel Squat + 2.2%
- Full Squat + 6.2%
- Above Parallel Squat + 2.7%
Of course, this doesn’t mean that if you don’t do full squats, your glutes are doomed to stay in the muscle-building slow lane.
Squats aren’t the only show in town. There are plenty of other lower-body exercises you can do, such as the same leg chain lunge, step ups or the Bulgarian split squat.
These exercises allow you to work through a larger range of motion while your torso remains upright. As a result, they’re harder on your glutes while simultaneously being a lot easier on your spine.
Same Leg Chain Lunges
Bulgarian Split Squat
Contrary to what the exercise police might say, there is no “one size fits all” recommendation when it comes to the question of how deep you should squat.
You should squat to a depth that allows you to maintain good form. By that, I mean you should go no deeper than the point where you lose the tight arch in your lower back. This may be slightly below or slightly above parallel.
It’s far better to be an inch or two on the high side than to go too deep and end up with a crippling back injury because of it. Even squats done above parallel are still deep enough to make your quads bigger and stronger.
However, it is important to have some kind of consistent point of reference that you can use to measure your progress.
Don’t delude yourself into thinking that you’re increasing your strength when all you’re really doing is decreasing your depth. Have a firm standard for what constitutes a squat, and stick to it.
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