Squat Depth: A Repeatable Range of MotionFor progressive overload, squat depth is important. If you squat to a particular depth one day, then the next day you add a little bit of weight but squat to a different depth—whether too high or too deep—you have changed not only the minimum force needed to perform the work but also the distance part of the work equation. While the work changed, it did not change in the manner anticipated by your programming and reflected in your training log
Squat Depth – A Repeatable Range of Motion
The range of motion (ROM) of any barbell lift describes the total movement that occurs around a lifter’s joints—from the start of the lift to its completion—using easy-to-confirm visual markers. The ROM may come from competitive lifting rules, such as bench press rules that limit how wide a lifter’s grip may be before the movement is no longer a bench press. Or, it may be a simple deduction from anatomy and common sense; there’s only one place a deadlift can start and only one place an overhead press can end up. A lift’s ROM gives it definition. Successful PR attempts for the squat, press, bench press, and deadlift depend, in part, on whether you completed the entire ROM, like checkpoints on a racecourse. Miss one and the lift is no good.
ROM is important, but the concept is at risk of getting lost in semantics. After all, the ROM for every lifter is a little bit different. A very tall, short-armed lifter will have a bigger deadlift ROM than a short, long-armed lifter. This happens because the start and end positions are independent of the lifter’s unique build. The lift starts on the floor and ends with the lifter standing tall with fully extended hips and knees. One lifter, however, had much farther to pull. (Read here for more on How Anthropometry Affects Your Lifts.) Why don’t all lifters set up their deadlifts so that everyone performs the same amount of work? One reason is practicality; it is much easier to identify a ROM by how a lift looks than by how far the bar travels. Another reason is that there is no “standard” distance that provides the best training effect or best test of strength for all people.
More importantly, ROM is not meant to compare one lifter to another. It sets a standard for you to perform your lifts, consistently and with effective and safe form. For a closer look at the need for consistent ROMs, let’s look at one of the less-talked-about reasons why depth is important in the barbell squat.
ROM in the Squat
The squat model that we teach has a threshold ROM at the bottom of the movement—a minimum depth defined by the crease of your hip dropping below the top of your knee. Also, there is such a thing as the squat being “too deep.” When we coach the squat, one of our goals is to help maintain the lifter’s ROM within the prescripts of this model. Not only does this model promote knee safety, the training effect of the squat, and adherence to lifting competition rules, but it also creates a definable, repeatable ROM.
The most useful exercises for overall strength development are big, multi-joint lifts that cause a lot of training stress with relatively few sets and reps. They train large amounts of muscle mass using big ROMs. And because we mostly use barbells, the best lifts are those that we can load incrementally from broomstick-sized weights to as much as any human can lift, ever. These criteria help maximize the effect you get from lifting weights, generating systemic stress that signals your body to get stronger. This systemic stress is related to the amount of overall physical work you do under the bar, which is, in turn, defined by each lifts ROM.
Squats and Work
Work is a measure of energy transfer when a force causes movement. Measured in Joules (J), work is the product of force times distance. In barbell training, force is a product of the weight we lift, and gravity gives definition to the barbell’s weight. A 300 lb. squat only has meaning in the context of the earth’s gravitational pull. We take that for granted, but the important part is that gravity only pulls straight down. If we care about the weight on the bar—and we do—we are concerned with work against gravity or the vertical displacement of the bar through the lift’s ROM. This is the distance portion of the work calculation.
As we said, the weight determines the amount of force in the work calculation—or, at least, the minimum amount of force needed to move the bar. When you complete a repetition, we know that you applied at least the amount of force needed to create movement vertically against gravity. If you add weight to the bar, the minimum force you need to accomplish the work of completing the ROM goes up. It takes more force to move 305 lb. than it does to move 300 lb. work, then, is the way that we try to measure force. In normal gym settings, we cannot know exactly how much force you used to move the barbell, only that it exceeded the amount of force that would have normalized the gravitational pull on the bar.
The more work you perform, the more training stress you get per rep, the stronger you get. There are other ways to generate productive training stress, but the main lifts all involve movement and work against gravity.
Progressive Overload and Squat Depth
Progressive overload has been a part of strength training since Milo of Croton and is one of the crucial factors for building strength. The concept is often thought of as merely increasing the weight on the bar. The load on the bar, however, is one of several factors that makes up training stress. Progressive overload means increasing the training stress over time, encompassing several variables such as the frequency of training, exercise selection, the number of productive sets and reps, and the intensity of the lift.
For most novice lifters, the only variable from workout-to-workout is the weight on the bar, because that is the smallest and most direct change we can make that will affecting the lifter’s training stress. The novice lifter starts with a set organization of training stress: typically, the four main lifts, performed for sets of five at a volume sufficient to induce training stress for an extended period of time. The lifter adjusts the stress by lifting a little bit more weight each time they train, increasing the stress slowly, and causing their body to adapt continually to that small change, making them stronger.
In this controlled, progressive overload, squat depth becomes important. If you squat to a particular depth one day, then the next day you add a little bit of weight but squat to a different depth—whether too high or too deep—you have changed not only the minimum force needed to perform the work but also the distance part of the work equation. While the work changed, it did not change in the manner anticipated by your programming and reflected in your training log.
One of the advantages of consistent lifting form is that it leads to predictable training responses. If the squat is much lower, the amount of work might have increased significantly. This doesn’t mean that the training stress was unproductive—not necessarily—but a change in depth represents inconsistency in your training. When we are concerned with as little as 2.5 lb. changes in the weight on the bar, inconsistently executed form is a problem that undermines the predictability of your adaptation to training.
The need for a consistent ROM makes visual depth markers preferable to depth by feel or by some internally-defined criteria. Setting the target as the crease of your hip dropping below the top of your patella makes depth something that you can see in your videos, something your coach can address, and something most powerlifting judges can judge accurately. If, instead, you defined your ROM by feel, you will have trouble calibrating your depth from session-to-session, set-to-set, and squat-to-squat.
A defined visual ROM is verifiable and repeatable, giving you the ability to stay consistent and adjust the stress of training, predictably. When you squat to depth, and that depth is just below parallel, your squat is a squat today, tomorrow, and for every PR.
 “Milo’s strength was legendary, and even though he lived in the 6th Century BC, records of his career survive and speak to a man whose strength and skill at wrestling were as close to mythological as anyone in history has been. There are many stories about him, but the most famous is that he began lifting a calf every day from the time it was very young until it was a full grown, 4-year-old bull. As the animal grew, Milo adapted to lift it, and his strength grew in tandem—perhaps the most gradual and most protracted linear progression in history.” (from Early Barbells and the Physical Culture Movement)