The hack squat muscles worked are primarily the quadriceps, with the gluteus maximus and hip adductors assisting and the hamstrings, calves, and core playing supporting roles.
This guide breaks down which muscles a hack squat works and how much each one contributes, then compares the hack squat with the leg press and covers what to look for in a home 3-in-1 machine.
Quick Answer: A hack squat primarily works the quadriceps, with the gluteus maximus and hip adductors as secondary movers and the hamstrings, calves, and core assisting as stabilizers. Foot placement and squat depth shift the emphasis, so a lower foot position loads the quads more while a higher position adds glute and hamstring work.
Key Takeaways
- What it is: A hack squat is a machine squat on a fixed angled track that removes the balance and spinal loading demands of a barbell squat.
- Main target: A hack squat is a quadriceps-led movement, and the gluteus maximus and hip adductors take the next largest share.
- Why the quads win: The fixed back pad holds your trunk upright while deep knee flexion keeps the knee extensors under load through a long range.
- Shift the emphasis: Raising your feet on the footplate and sinking deeper brings the glutes and hamstrings in, while a lower foot position keeps the work on the quads.
- vs leg press: You can leg press more weight because the sled and seat count as part of the load, but the hack squat drives more knee extensor work.
- Home option: A 3-in-1 machine such as the RitFit BLP01 covers hack squat, leg press, and calf raise in a 20.3 sq ft footprint.
Which Muscles Does a Hack Squat Work?
A hack squat works the quadriceps as the primary mover, with the gluteus maximus and hip adductors assisting and the hamstrings, calves, and core supporting. The fixed back pad holds your torso upright so the knee extensors stay loaded through the whole rep.
- Quadriceps: The rectus femoris and the three vastus muscles drive the press, and they keep tension because the back pad removes the balance work a barbell squat demands.
- Gluteus maximus: The glutes extend your hips as you come out of the bottom, and they take on a larger share once you descend below parallel.
- Hip adductors: The adductor group on the inner thigh assists hip extension, which is why a hard set can leave the inner thighs as sore as the quads.
- Hamstrings: The hamstrings help extend the hip and steady the knee, and a higher foot placement on the platform increases their contribution.
- Calves and core: The calves work through the ankle as you drive, while the core and spinal erectors hold your position against the pad.
A 2024 biomechanical review of the squat explains the mechanism: forward trunk inclination reduces the knee flexion moment while forward tibia inclination increases it, and the hack squat fixed back pad keeps the trunk more upright than a free-weight squat[1]. A separate study of bilateral squatting found that the trunk to tibia angle at peak knee flexion predicts the hip to knee moment ratio, so an upright trunk paired with a forward shank biases the movement toward the knee extensors[2].
Depth matters as much as the machine. Quadriceps muscle activation during maximal isometric squatting peaked at 90 degrees of knee flexion, which is a practical argument for taking your thighs to at least parallel instead of stopping high[3].
Foot placement is the simplest dial you control. Moving your feet lower on the footplate increases knee flexion and keeps the emphasis on the hack squat target muscles, while a higher placement shifts more of the work to the glutes and hamstrings.
For the muscles working alongside the legs, see our guide to shoulder press muscles worked.
"The best quad exercise in the world is going to be your hack squats. You're always going to get more press on the front thighs. If you can get into a hack squat machine and it does not hurt, this is the ultimate exercise to build those frontal thighs."
Jay Cutler, Four-time Mr. Olympia, Cutler Nutrition, Jay Cutler Shares the Best Quad Exercise in the World to Build Size
What Is a Hack Squat?
A hack squat is a machine leg exercise that locks your back against an angled pad and drives the load through shoulder pads as you squat along a fixed track. The machine removes the balance and spinal loading demands of a barbell squat while keeping the squat pattern intact.
- Fixed path: The sled rides a set track, so you focus on driving with your legs instead of balancing a bar.
- Shoulder pads: The weight rests on your shoulders and upper back through padded yokes, close to where a barbell sits.
- Back support: The angled back pad holds your torso, which cuts lower-back strain versus a free-weight squat.
A home hack squat machine such as the RitFit BLP01 3-in-1 Leg Press and Hack Squat Machine combines this movement with a leg press, so you can run a full lower-body day without a barbell, rack, or spotter. For the free-weight version of the same pattern, see our comparison of the hack squat vs barbell squat.
How to Do a Hack Squat
A hack squat is performed by setting your feet shoulder-width on the platform, lowering your shoulders under the pads, and releasing the safety before you descend. Adjust the machine first so your knees track over your toes without strain.
- Setup: Adjust the back pad and footboard so your knees track over your toes without strain.
- Descent: Bend your knees and let your hips sink until your thighs reach at least parallel, keeping your heels flat.
- Drive: Push through the middle of your foot and extend your knees and hips together to return to the start.
- Control: Keep the descent smooth and pause briefly at the bottom before pressing up.
For a step-by-step walkthrough of setup and switching between positions, see our guide on how to use a leg press hack squat machine.
How Is a Hack Squat Different From a Leg Press?
A hack squat keeps your torso upright against an angled pad, whereas a leg press has you reclined and pushing a sled with your feet. The hack squat mimics a squat pattern with deeper knee flexion, while the leg press allows heavier, more back-friendly loads.
| Feature | Hack Squat | Leg Press |
|---|---|---|
| Movement | Weight on back, upright torso, angled track | Reclined sled push, back fully supported |
| Primary movers | Quads, then glutes and adductors | Quads, glutes, hamstrings |
| Quad emphasis | Very high, deep knee flexion | High, adjustable via foot position |
| Core and lower back | Moderate stabilization | Minimal, back supported |
| Max load | Moderate to high | Very high |
| Best for | Quad-focused development, squat carryover | Overall leg mass, back-friendly heavy loading |
Comparisons are general movement characteristics. Individual results vary by machine setup, foot placement, and training experience.
Machine geometry explains part of the load gap, because the machine itself counts as resistance. One study determined total leg press load as the loaded plates plus the weight of the sled[4], and a seated leg press study calculated effective load by adding the moving seat weight and external stacks to body weight[5].
That is one reason your leg press numbers run well ahead of your hack squat numbers, and it is a load accounting difference rather than a strength difference. For the leg press side of this comparison, see our guide on leg press muscles worked and browse the full leg press machine collection.
"Great hack squat so far, I havent tried leg press yet but im sure it'll be smooth like the squat. Worth every penny so far."
Garrett M. Verified Buyer, RitFit BLP01 3-in-1 Leg Press and Hack Squat Machine
Which Should You Use: Hack Squat or Leg Press?
Choose the hack squat when quad development is your main goal, and choose the leg press when you want heavy, back-supported volume. Most programs use both across a training week.
- Pick the hack squat for: quad growth, squat carryover, and a deeper range of motion.
- Pick the leg press for: maximal loading, a beginner-friendly setup, and lower-back-friendly volume.
- Use both: Let the hack squat handle quad-focused work and the leg press cover volume and glute emphasis.
The RitFit Gazelle Pro 3-in-1 Leg Press and Hack Squat Machine lets you train both patterns at home, which matters if your quads are the lagging muscle group and you still want the volume work.
Why Add a Hack Squat to a Home Gym?
A home hack squat machine gives you a loaded squat pattern without a barbell, rack, or spotter, so you can train heavy leg work in a small space. A 3-in-1 unit such as the RitFit BLP01 or Gazelle Pro adds a leg press and calf raise to the same footprint.
- Safer than a barbell: The machine guides the path and catches the load, so you can train close to failure without a spotter.
- Back-friendly: The angled pad supports your torso, which cuts lower-back strain versus a free-weight squat.
- Space saving: A 3-in-1 unit replaces several machines in about 20.3 sq ft of floor space.
- Consistency: Training at home removes the commute and the wait for a machine on a busy leg day.
A 6 week quadriceps dominant training program that included hack squat variations improved vastus lateralis motor unit recruitment and functional performance such as sit to stand and stair climbing in older adults[6]. That is a useful reminder that quad-focused machine work carries over to daily movement, not just to a bigger squat number.
For a compact setup, the RitFit Gazelle 3-in-1 adds more adjustability for taller lifters.
How to Choose the Right Hack Squat Machine for Your Home
A home hack squat machine is the right one when its capacity, footprint, and adjustability match your working weights and your room. A 3-in-1 unit that combines leg press, hack squat, and calf raise gives you the most lower-body coverage per square foot.
- Durability: Read the frame rating first. The RitFit BLP01 carries a 1200 lb weight capacity with a 572 lb overall dynamic capacity, the Gazelle is rated to 1500 lb, and the Gazelle Pro is rated to 2000 lb.
- Versatility: A 3-in-1 machine switches between leg press, hack squat, and calf raise, and the BLP01 gives you five lower foot plate positions plus three upper positions for stance changes.
- Warranty: Check the current frame and parts coverage on the product page before you order, since terms are updated over time.
- Performance: The BLP01 runs on a linear bearing slide with three lockout positions, so you can pause or end a heavy set without help.
- Footprint: The BLP01 occupies 20.3 sq ft at 55.9 inches tall, so measure floor space and ceiling clearance before delivery day.
- Value: Compare the current price against how many stations the machine replaces, and weigh that against the cost of separate leg press, hack squat, and calf raise equipment.
If you want the whole leg setup in one order, the RitFit BLP01 Full Leg Workout Package bundles the machine with the accessories you will want later. Match the shortlist to your room first, then your training level, then your budget.
"For the money, especially when it is discounted, the RitFit BLP01 does what it is supposed to do: it gives you a smooth, functional leg press and hack squat setup that most home gym lifters can actually afford."
Michael Tabers, Equipment Reviewer, The Jungle Gym Reviews, RitFit BLP01 Review: Best Budget Leg Press Hack Squat (The Jungle Gym Reviews)
How Many Sets and Reps Should You Do?
Start with the empty carriage to learn the range of motion, then build up over several sessions. For hypertrophy, 3 to 5 sets of 8 to 12 reps with 60 to 90 seconds of rest works well, while 3 to 4 sets of 5 to 8 reps suits strength work.
- Start light: Begin with the empty carriage and add small plates once the movement feels stable.
- Rep ranges: Use 8 to 12 reps for muscle growth and 5 to 8 reps for strength and loading practice.
- Frequency: Train the hack squat 1 to 2 times per week, allowing 48 hours between lower-body sessions.
- Add weight: Increase the load when you complete the top of the rep range with clean form on every set.
Progression is about control, not speed. Add weight in small steps, keep your working weight well below what you could leg press, and expect the hack squat to feel heavier per plate for the first few weeks.
Common Hack Squat Mistakes to Avoid
The most common hack squat mistakes are dropping too fast, lifting your heels, cutting depth short, and adding weight before the pattern is stable. Each one reduces quad work or loads your knees unnecessarily.
- Bouncing at the bottom: Descend under control and pause briefly instead of rebounding out of the hole.
- Heels lifting: Keep your feet flat so the load stays over the middle of your foot.
- Half reps: Take your thighs to at least parallel to get the full quad range.
- Going too heavy too soon: Build the pattern first, then add load in small steps.
- Ignoring knee pain: Stop and reduce depth if you feel sharp knee pain, and check your foot position.
If you prefer the attachment route over a dedicated machine, our hack squat rack attachment guide covers that setup separately. Squatting on a guided bar is another option, and the Smith machine hack squat keeps the same foot placement rules.
FAQs About the Hack Squat
What is a hack squat?
A hack squat is a machine leg exercise where you squat down and up on a fixed angled track with a padded back support and shoulder pads holding the weight. It mimics a barbell back squat pattern with the balance and spinal loading demands removed.
What muscles does a hack squat work?
The hack squat primarily works the quadriceps, with the glutes and hamstrings as secondary muscles. Calves, core, and spinal erectors assist as stabilizers. Foot placement and depth shift the emphasis. A lower foot position drives more quad work, while a higher placement adds more glute and hamstring involvement.
Is a hack squat better than a leg press?
For quad development the hack squat is generally the better choice because its upright torso and deeper knee flexion put the quads under more stretch. The leg press allows heavier, more back-friendly loads and spreads work across the whole leg, so most programs use both.
Is the hack squat harder than the leg press?
Most lifters find the hack squat harder per rep because it requires more core activation and a deeper range of motion. You can typically leg press more weight, since the reclined leg press supports the back and shares the load across more muscles.
Can I do hack squats at home?
Yes. A home hack squat machine such as the RitFit BLP01 or Gazelle Pro combines leg press and hack squat in one footprint. You can train the squat pattern safely at home without a barbell, rack, or spotter. The machine guides the movement, so setup is simpler than learning free-weight squats.
How much weight should I start with on a hack squat?
Start with the empty carriage to learn the range of motion, then add small plates as you feel stable. Progress with controlled reps rather than big jumps, and keep working weight well below what you could leg press, especially at first.
Do hack squats work the hamstrings?
Yes. The hamstrings assist during a hack squat, but they work far less than they do in a Romanian deadlift or a leg curl. A higher foot placement and a controlled descent increase hamstring involvement. The quadriceps still drive the movement.
How do I make hack squats target my glutes more?
Raise your feet higher on the footplate and let your knees travel slightly wider so your hips take on more of the load. Going deeper below parallel also increases glute involvement. Keep the load moderate at first so your position stays stable.
Does foot placement change which muscles a hack squat works?
Yes. A lower foot position increases knee flexion and keeps the emphasis on the quadriceps, while a higher foot position shifts more of the load to the glutes and hamstrings. Squatting deeper and testing both positions at the same load shows where you feel the work.
Conclusion
A hack squat works the quadriceps first, with the gluteus maximus and hip adductors close behind and the hamstrings, calves, and core assisting. That quad bias comes from the fixed back pad holding your trunk upright through deep knee flexion.
Start light, build your depth, and change your foot position when you want more glute and hamstring work. Pair the hack squat with a leg press and calf raise for a complete leg day, and check the RitFit discount guide for current offers before you buy.
Disclaimer
This article is for general education only and does not replace professional medical, fitness, or safety advice. Consult a qualified trainer or healthcare provider before starting a new exercise program, especially if you have existing knee, back, or joint conditions.
References
1. Straub RK, Powers CM. A Biomechanical Review of the Squat Exercise: Implications for Clinical Practice. Int J Sports Phys Ther. 2024;19(4):490-501. doi:10.26603/001c.94600. PMCID: PMC10987311
2. Graber KA, Halverstadt AL, Gill SV, Kulkarni VS, Lewis CL. The effect of trunk and shank position on the hip-to-knee moment ratio in a bilateral squat. Phys Ther Sport. 2023;61:102-107. doi:10.1016/j.ptsp.2023.03.005. PMCID: PMC10518215
3. Marchetti PH, Jarbas da Silva J, Jon Schoenfeld B, et al. Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise. J Sports Med (Hindawi Publ Corp). 2016;2016:3846123. doi:10.1155/2016/3846123. PMCID: PMC4967668
4. Jakobsson J, Theos A, Malm C. Effects of Different Types of Lower Body Resistance Exercise on Upper-body Strength in Men and Women, with Special Reference to Anabolic Hormones. Int J Exerc Sci. 2021;14(3):1052-1069. doi:10.70252/DYRH9028. PMCID: PMC8439705
5. Migliaccio GM, Dello Iacono A, Ardigò LP, et al. Leg Press vs. Smith Machine: Quadriceps Activation and Overall Perceived Effort Profiles. Front Physiol. 2018;9:1481. doi:10.3389/fphys.2018.01481. PMCID: PMC6206431
6. Followay B, Holland T, Rowley L. Effects of a Quadricep-Dominant vs. Functional Training Program on Activities of Daily Living, Functional Performance, and Motor Unit Recruitment in Older Adults. Int J Exerc Sci. 2025;18(8):1096-1113. doi:10.70252/YHYC9630. PMCID: PMC12510696
