Exercise library / Legs
Hack squat (machine)
Legs · Machine
The hack squat machine holds your back against a pad and runs the weight on a fixed track. You still squat, but nothing is asking your spine to hold the load in place.
That changes what limits the set. On a barbell squat you often stop because bracing gives out. Here you stop because your legs do, which is the point of the exercise.
Sets, reps and RIR
Machines and cables hold the path for you, so you can work closer to failure than with free weights.
RIR means reps in reserve: how many you could still have done when you racked it. RIR 2 is two short of failure.
How to do it
- Set your back and shoulders against the pads and place your feet on the platform, roughly hip to shoulder width.
- Release the safety handles and take the weight with your legs, not by letting it settle onto your knees.
- Lower by bending the knees and hips together, keeping the whole foot on the platform.
- Go down until your thighs pass parallel, as far as you can without the lower back peeling off the pad.
- Drive back up through the middle of the foot and stop just short of locking the knees.
Common mistakes
- Heels lifting at the bottom
- If the heel comes off the platform the knee takes the whole load. Move the feet slightly higher up the platform, or stop the rep a little sooner.
- Knees caving inward
- The machine will let you keep going with the knees tracking inside the feet. Push the knees out over the second and third toe on the way up.
- Half reps with a stacked machine
- Loading a hack squat is easy and stopping short is easier. A shallow rep with six plates builds less than a full one with three.
- Slamming into the lockout
- Snapping the knees straight at the top gives you a rest and gives the joint a jolt. Stop just before straight and go again.
How it differs from the neighbouring variants
The leg press puts you in a seated position with the hips more bent, which brings the glutes and hamstrings in more. The hack squat is more upright and more quad-dominant.
A barbell back squat trains the same legs plus everything that holds you together. It builds more overall, and it is the one where bracing ends the set first.
What it suits
The hack squat works as the main leg exercise on a day you are not squatting, or straight after squats when you want more quad volume without more spinal load. Six to fifteen reps, and zero to two in reserve. The safety handles are right there, so the last set can be an honest one.
Muscles worked
Primary: Quads.
Secondary: Glutes, Adductors, Abductors.
Estimate your one-rep max
Epley's formula, from a set you have actually done. It is an estimate, and it drifts above eight reps, so keep the input between one and twelve.
Enter a set to see the estimate.
What it is called elsewhere
- Norsk Hack squat (maskin)
- Svenska Hack squat (maskin)
- Dansk Hack squat (maskine)
- Deutsch Hack Squat (Maschine)
- Español Sentadilla hack (máquina)
- Italiano Hack squat (macchina)
- Português Agachamento hack (máquina)
- Русский Гакк-приседания
- Français Hack squat (machine)
Related legs exercises
athlate logs this exercise, keeps the numbers, and tells you what you lifted last time.