Barbell Hack Squat
The barbell hack squat has you holding a barbell behind your legs at arm's length, then squatting down and standing back up while the bar stays close to your calves and hamstrings the entire time. It's an old-school way to load a squat pattern that shifts more emphasis onto the quads than a standard back squat, since the weight sits behind you instead of on your shoulders, keeping your torso more upright throughout the lift.
Why it works
Holding the bar behind your legs instead of on your back changes where your center of gravity sits relative to your knees. That position lets you keep your torso more vertical through the squat, which shifts a larger share of the work onto the quadriceps compared to a back squat, where a more forward-leaning torso brings the hips and lower back further into the lift. Your forearms and hamstrings get pulled in as secondary muscles here too, the forearms simply from gripping the bar behind you for the whole set, and the hamstrings helping stabilize the knee as you descend and stand.
Set up
- Stand with a barbell on the floor behind your heels.
- Squat down and grip the bar with both hands, palms facing behind you.
- Stand up holding the bar at arm's length behind your legs, feet roughly shoulder-width apart.
- Brace your core and keep your chest tall before the first rep.
How to do it
- Bend your hips and knees to squat down, letting the bar travel down close behind your calves and hamstrings.
- Keep your torso upright and your heels planted throughout the descent.
- Squat down until your thighs are roughly parallel to the floor, or as deep as you can control with a flat back.
- Drive through your whole foot to stand back up, keeping the bar tracking close behind your legs.
- Finish standing tall with your hips fully extended before starting the next rep.
Form cues
- Bar stays close behind your calves the whole rep.
- Torso stays upright, this isn't a hinge.
- Heels stay planted through the descent.
- Grip tight, your forearms are working the whole set.
Breathing: Inhale and brace before you descend, hold through the bottom position, then exhale as you drive back up to standing.
Common mistakes
Losing grip on the bar partway through a set as the forearms fatigue.
Fix: Use chalk or lifting straps if grip is the limiting factor before your legs are actually fatigued, or reduce the weight until grip endurance catches up.
Letting the bar swing forward away from the legs during the squat.
Fix: Actively keep the bar dragging close behind your calves and hamstrings the entire descent and ascent.
Rounding forward at the bottom to compensate for limited ankle mobility.
Fix: Reduce depth slightly and work on ankle mobility separately, standing on a slight heel wedge if that helps you stay upright.
How to program it
- 3 to 4 sets of 8 to 12 reps at a moderate to challenging weight suits this well as a quad-focused accessory squat.
- Once or twice a week works for most lifters, depending on how much other knee-dominant squatting is already in the week's programming.
- Place it after your primary squat or deadlift pattern in a session, since grip fatigue here compounds with anything else that taxes the forearms.
- This is a good replacement for a leg press when you want to keep working stabilizer muscles that a machine would otherwise take out of the equation.
Safety notes
- Keep the bar tracking close to your legs at all times; a bar that drifts forward pulls you off balance and strains the lower back.
- Stop the set if your grip gives out before your legs do, rather than dropping into an uncontrolled bottom position.
Exercise profile
- Force
- Push
- Mechanics
- Compound
- Category
- Strength
Frequently asked questions
How many sets and reps for the barbell hack squat?
3 to 4 sets of 8 to 12 reps at a moderate to challenging weight works well as a quad-focused accessory movement.
What muscles does the barbell hack squat work?
The quadriceps do most of the work here, since holding the bar behind you keeps your torso upright and shifts emphasis away from the hips. The forearms and hamstrings help out as secondary stabilizers, the forearms from gripping the bar and the hamstrings from controlling the knee.
Why do I keep losing my grip during hack squats?
The bar sits behind you at an awkward angle for your forearms, so grip often fatigues before your legs do. Try chalk, lifting straps, or simply reducing the weight until your grip endurance improves.
Barbell hack squat vs machine hack squat: what's the difference?
The barbell version has you gripping the weight freehand behind your legs, which adds a grip and balance demand. The machine version fixes the bar path on a sled, removing most of that balancing act so you can focus purely on the squat pattern.
How much weight should I start with for the barbell hack squat?
Start light, well under what you'd back squat, since grip and balance are the limiting factors here before your legs are. Add weight gradually once you can hold the bar behind your legs through a full set without it drifting forward.