Hack Squat
The hack squat sits between a barbell squat and a leg press: you stand and squat under load, but the machine's back pad and fixed track remove the balance demand. That support lets you push the quads through deep knee flexion with less spinal loading, which is exactly why bodybuilders lean on it for quad size. It is also a forgiving place to learn deep squat mechanics.
How to do the hack squat, step by step
- Step into the machine with your back and shoulders set firmly against the pads.
- Place your feet on the platform around shoulder width, low enough that the knees can travel forward.
- Release the safety handles and take the load on your shoulders.
- Lower for 2 to 3 seconds, letting the knees drive forward and down until your thighs at least reach parallel to the platform.
- Pause briefly in the bottom without bouncing.
- Drive through the whole foot to stand, stopping just short of a hard knee lockout.
Form cues that fix most reps
Keep your whole back pressed into the pad from start to finish.
Sink deep — the bottom third of the rep is what makes the hack squat worth doing.
Lower on a strict three-count when in doubt about control.
Common mistakes (and the fix)
Hack Squat sets and reps
Match the rep range to your goal, not the other way around. These are the standard evidence-based ranges:
| Goal | Sets × Reps | Rest |
|---|---|---|
| Strength | 3–5 × 3–6 | 2–3 min |
| Muscle growth | 3–4 × 8–12 | 60–90 sec |
| Endurance | 2–3 × 15–20 | 30–60 sec |
How our free programs prescribe it
Hack Squat FAQ
What muscles does the hack squat work?
The quads take the bulk of the load because the back support keeps your torso upright and pushes the knees into a large range of motion. The glutes assist at the bottom and the adductors help out of the hole, but this is first and foremost a quad builder.
Hack squat vs leg press — which is better for quads?
Both load the quads heavily; the hack squat usually allows a deeper knee bend and a more squat-like position, while the leg press is easier to set up and push to failure. Pick whichever your knees and gym allow, or rotate them across training blocks.
Are hack squats hard on the knees?
The deep knee travel is demanding but not inherently harmful — knees adapt to loads they are given time to adapt to. Start with moderate weight and full range, add load slowly, and avoid grinding through sharp pain rather than avoiding depth altogether.
More quads exercises
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