Is this the same as the hack squat machine?

No. The sled Hack Squat machine has you lean back against a pad with the load on your shoulders, while this version keeps you standing free with the Smith bar held behind your legs. It is the Smith machine take on the old-school Barbell Hack Squat, and the Landmine Hack Squat is another way to load the same quad-focused pattern.

How is it different from a Smith machine squat?

In the Smith Machine Squat the bar rests across your upper back, so you can load it much more heavily. Here the bar hangs from your arms behind your legs, which keeps the torso more upright and the work on the quads, but your grip limits how much you can hold.

Should the bar touch my legs?

It should travel close behind your legs without dragging along them. The rails hold the bar on its path, so if it scrapes your calves or the backs of your thighs, move your feet slightly farther forward.

What can I do if my grip gives out before my legs?

Lifting straps are the simplest fix, since they let the legs work to failure instead of the hands. Make sure you can still rotate the bar back onto a hook or let it settle on the safety stops before you rely on them.

Can I put plates under my heels?

Yes. A small plate or wedge under the heels helps if tight ankles stop you from reaching depth with flat feet, and it shifts a little more of the work onto the quads.

Where does it fit in a leg workout?

Most lifters use it as an accessory after their main squat or leg press, for 3 or 4 sets of 8 to 15 reps. That rep range suits the moderate loads your grip can hold.

Smith Machine Hack Squat

What Is the Smith Machine Hack Squat?

Smith Machine Hack Squat is a compound exercise that primarily targets the quads and also engages the glutes, adductors and lower back. It is an intermediate-level movement in which you hold a Smith machine bar behind your legs with straight arms and squat it up and down along the machine's fixed rails.

This is the Smith machine version of the old-school Barbell Hack Squat, where the bar hangs behind the body instead of resting on the back. It is a different exercise from the plate-loaded sled Hack Squat machine with its shoulder pads and back rest, and from the Smith Machine Squat, where the bar sits across the upper back.

Holding the weight behind the legs keeps the torso fairly upright and lets the knees travel well forward, which puts most of the work on the quadriceps rather than the hips and hamstrings. The rails take care of balance and bar path, so you can stand just in front of the bar and let it travel close behind your legs instead of dragging it up the calves and thighs as you would with a free barbell. A narrower stance and slightly elevated heels push the work further onto the quads, while a wider stance brings in more of the adductors. The upper traps and forearms work hard to hold the bar, and grip is usually what limits the load.

The Smith Machine Hack Squat suits lifters who want extra quad volume without a bar across the upper back, and it usually sits after the main squat or leg press of a leg session as a moderate-to-higher-rep accessory. If you are new to squatting, build a solid Bodyweight Squat and Dumbbell Goblet Squat first, so the depth and knee travel feel familiar before you add a bar behind you.

Muscles Worked

MuscleActivation

Vastus Lateralis: Primary
Vastus Medialis: Primary
Gluteus Maximus: High
Rectus Femoris: High
Adductor Magnus: Medium
Erector Spinae: Medium
Flexor Carpi Radialis: Low
Flexor Carpi Ulnaris: Low
Soleus: Low
Upper Trapezius: Low

Instructions

Set the Smith machine safety stops just below the depth you plan to reach, and hook the bar a little below knee height.
Stand facing away from the bar with your heels just in front of it and your feet about hip to shoulder width apart, toes pointing forward or slightly out.
Squat down, reach back and grip the bar with an overhand grip, hands just outside your hips and arms straight.
Brace your core, rotate the bar off the hooks and stand up tall, chest up and shoulders pulled back.
Take a breath and lower yourself by bending your knees and letting them travel forward, keeping your torso fairly upright as your hips drop straight down.
Keep your arms straight and your heels flat as the bar slides down the rails just behind your legs.
Descend until your thighs are about parallel to the floor, or as deep as you can go with a flat back.
Drive through your whole foot to stand back up, keeping your knees in line with your toes.
Finish standing tall without snapping your knees into lockout, then start the next rep.
After the last rep, lower the bar and rotate it back onto the hooks before you let go.

Common Mistakes

Turning it into a deadlift
Pushing the hips back and folding the torso forward shifts the work to the hips and lower back, so let the knees travel forward and lower the hips straight down.
Standing the wrong distance from the bar
Standing too close drags the bar up your calves and thighs, while standing too far forward pulls your arms behind you, so set your heels just in front of the bar.
Heels lifting off the floor
Rising onto the toes at the bottom loads the knees and costs balance, so keep the whole foot down and raise the heels on a small plate if your ankles are tight.
Rounding the lower back
Letting the back round to reach more depth puts the strain on the spine, so stop at the depth where you can still keep the chest up and the back flat.
Knees caving in
Letting the knees fall inward as you stand up strains the inside of the knee, so keep them tracking over the toes.
Cutting the depth to lift more
Loading the bar so heavy that you only manage a shallow dip takes away most of the quad work the exercise is meant to give.

Injuries

Smith Machine Hack Squat is a medium risk exercise when performed with proper technique. The knees take the most stress, because the bar behind the legs lets them travel far forward into deep flexion under load. The lower back is at risk if it rounds at the bottom, and holding the bar behind you with straight arms can strain the front of the shoulders and wear out the grip before the legs are done.

Set the safety stops just below the deepest point you plan to reach before you load the bar, so a failed rep lands on the stops rather than on you. Start light while you learn the setup, keep the chest up and the back flat, and drive through the whole foot. If tight ankles lift your heels or round your back at depth, put a small plate or wedge under your heels instead of forcing the range.

To regress, return to the Dumbbell Goblet Squat or the Bodyweight Squat. Once the pattern is solid, the free-bar Barbell Hack Squat adds a balance demand, and the sled Hack Squat machine lets you load the quads more heavily without relying on grip. Stop the set if you feel sharp knee pain, pain in the lower back, or a pinch at the front of the shoulder.

Overview

Primary Focus: Quads
Equipment: Smith machine
Modality: Strength
Difficulty: Intermediate

Alternative Exercises

Frequently Asked Questions

Q: Is this the same as the hack squat machine?: No. The sled Hack Squat machine has you lean back against a pad with the load on your shoulders, while this version keeps you standing free with the Smith bar held behind your legs. It is the Smith machine take on the old-school Barbell Hack Squat, and the Landmine Hack Squat is another way to load the same quad-focused pattern.
Q: How is it different from a Smith machine squat?: In the Smith Machine Squat the bar rests across your upper back, so you can load it much more heavily. Here the bar hangs from your arms behind your legs, which keeps the torso more upright and the work on the quads, but your grip limits how much you can hold.
Q: Should the bar touch my legs?: It should travel close behind your legs without dragging along them. The rails hold the bar on its path, so if it scrapes your calves or the backs of your thighs, move your feet slightly farther forward.
Q: What can I do if my grip gives out before my legs?: Lifting straps are the simplest fix, since they let the legs work to failure instead of the hands. Make sure you can still rotate the bar back onto a hook or let it settle on the safety stops before you rely on them.
Q: Can I put plates under my heels?: Yes. A small plate or wedge under the heels helps if tight ankles stop you from reaching depth with flat feet, and it shifts a little more of the work onto the quads.
Q: Where does it fit in a leg workout?: Most lifters use it as an accessory after their main squat or leg press, for 3 or 4 sets of 8 to 15 reps. That rep range suits the moderate loads your grip can hold.