Hack Squat
Quad-building on rails — the machine squat that lets you chase depth safely.
Setup
- Back flat on the pad, shoulders under the pads.
- Feet mid-platform, hip-width.
How To Do It
- Lower under control until thighs pass parallel.
- Keep the whole foot pressing; knees track over toes.
- Drive up without slamming into lockout.
Breathing
Inhale down, exhale through the drive.
Common Mistakes
- Feet too low on the platform — knees take over everything; move them up.
- Bouncing the bottom — pause a beat instead.
Programming It
Three to four sets of 8-15.
Why This Exercise Works
The sled fixes the path and supports the back, so the quads take a larger share than in a free squat and the trunk takes almost none. It lets you push a leg session close to failure without the spinal cost that makes barbell squatting expensive.
Where You Should Feel It
Quads, more than almost any other leg exercise, with the back supported so nothing else limits you. Knee discomfort usually means the feet are too low on the platform.
Where It Fits in a Program
Quad-building on rails — the machine squat that lets you chase depth safely. This is main-lift work. Put it first, when your technique is still honest.
Progressing and Regressing It
To progress the hack squat: add a plate, or slow the eccentric to three seconds. To regress it: reduce the range to what the knees tolerate without pain.
Who It's For
Anyone chasing quad size, and anyone whose lower back cannot take squatting volume. The machine takes balance out entirely, so you can push close to failure safely.
Equipment and Substitutions
What you need for this one: a hack squat machine. A free-weight substitute from the list works, but you will need to control the path yourself — expect a lighter load for the same effort.
Related Exercises
- Belt Squat — Quads, Glutes
- Leg Press — Quads, Glutes
- Jump Squat — Quads, Glutes, Power
- Barbell Hack Squat — Quads, Glutes
- Sissy Squat — Quads
- Front Squat — Quads, Core, Upper Back
- Front-Foot-Elevated Split Squat — Quads, Glutes
- Band Squat — Quads, Glutes
Common Questions
What muscles does the hack squat work?
The hack squat primarily trains the quads, glutes.
How many sets and reps should I do?
Three to four sets of 8-15.
What are the most common hack squat mistakes?
Most often: feet too low on the platform; bouncing the bottom.
Do I need a hack squat machine to do this?
This version uses a hack squat machine, and it trains the quads, glutes. A free-weight substitute from the list works, but you will need to control the path yourself — expect a lighter load for the same effort.
Is this safe if I have an existing injury?
The hack squat loads the knee and ankle, so stiff ankles or an irritable knee will show up early. Sharp pain at a single point is the one to stop for; a general burn is not. Not medical advice.