Is a Prius anything like a Shelby Cobra Mustang? Sure they’re both cars and have similar parts, but they are nothing alike. The same thing can be said about the leg press when compared to the squat.
Both the leg press and squat are intended to strengthen the muscles of your legs, but the leg press has several limiting factors concerning the action of the movement compared to the squat… and the squat strengthens more than just your legs.
Elimination of stability
When jumping in the seat of the leg press to place your feet up onto the platform you’re simply moving a sled up and down on a set of tracks in order to lift the weight. The platform moves along a fixed track and your hips and lumbar are in a fixed position as you sit in the seat in order to lift the weighted platform.
Because you’re sitting in this fixed position and moving a platform along a set of tracks you are eliminating any need for stabilizing muscles to be activated in order for you lift and move the weight. This basically bleeds you of developing any strength throughout your core, or pillar like you would when resting a barbell on your back, or holding one in the racked position during a barbell front squat movement.
When you’re forced to stabilize the weight like you would with a barbell, dumbbell, or kettlebell during a goblet squat you are activating what is known as synergist muscles. Synergist muscles perform or help perform, the same set of joint motion as the agonists (the primary mover).
Synergist muscles act on movable joints. Synergists are muscles that facilitate the fixation action which in the case of you lifting a free weight such as a bar or kettlebell allows you to keep it steady during the up and down part of the movement.
As you see there is nothing for you to fixate when sitting in the driver’s seat of the leg press machine as the machine itself is facilitating the fixation action for you.
Butchering Your Range of Motion (ROM)
There’s no doubt when it comes to both the squat and the leg press that your average gym goer will find a way to destroy their ROM during both of these exercises. However, I would argue that with the leg press this almost seems to be a badge of honor with many guys.
I’m sure you know what I’m talking about when you see those guys in the gyms load up the leg press platform with damn near every 45 lb. plate in the gym. As if it’s not dangerous enough that they’re maxing out the machine itself they then get into the seat of the leg press with all of that weight hovering above them.
Photography by Bev Childress of Fort Worth, Texas
I’ve seen more videos of this on YouTube and Instagram than I care to admit and though these scenarios tend to provide a lot of humorous content for many comedians…such a ridiculous attempt is both scary and dangerous to me and I’m a professional strength coach.
What you generally see in these scenarios is a shitload of weight and the guy ends up moving his legs up and down only a couple of inches. This is a total waste of time in an attempt to build strength and on top of that is incredibly dangerous.
I admit I’ve seen many people butcher the squat as well, but in most cases, a guy’s ego can be crushed when trying to load up too much weight for the squat because when the bar is on your back you are directly going to feel that weight.
There are always exceptions and a village idiot exists everywhere you go, but for the most part, the ego would rather load that platform on the leg press than feel it on his, or her back.
Zero Functional Value
The squat is one of 7 foundational movements that allow you to live life as an able-bodied human being. When squatting you must be capable of demonstrating ankle mobility, knee flexion, and hip mobility when settling down into the squat movement.
When you sit on the leg press machine you’re not training yourself to be better, or more capable of picking something up off of the ground, or for even being able to do something as natural as to take a crap. Not to be gross, but this is where one of the biggest needs of the ability to squat came from.
With the leg press, you’re also not training yourself to be able to get into the squat position to take on tasks such as gardening, to work in low positions, or to get in and out of tight places like you might need to do with a home construction project.
The leg press is pretty much going to be more isolating to your quads in its application than anything else. You’re certainly not going to be able to demonstrate and train the hip hinge with the leg press either as your hips are locked into place.
If I had to guess there is virtually never going to be a situation in your life where you would sit in a fixed position and simply push a sled away from your body. However, there is going to be many situations that arise in your life where you’ll have to demonstrate to some level an ability to squat…even if it’s a partial attempt.
I believe there can be uses for the leg press, but for the most part, if you happen to be an able-bodied person you should practice to improve your squat on a frequent basis.
The squat is a functional movement. Just remember that a lack of mobility is a lack of function and a lack of function means a lack of mobility…and possibly stability.
If you want to work on a better understanding of squat movement patterns you can train with me at Brandon Richey Fitness in Buford, Georgia or remotely. I can talk about this stuff for hours and I think it’s important that everyone understands what it means when they make certain exercise choices.
Everyone is different, and we all need some help to figure out the best options for us based on our body’s abilities, age, sex, and ultimately, goals.