When it comes to the most intimidating machines in the gym, it has to be the hack squat. A monster of a machine, with an angled sled, shoulder pads, and back support that has you questioning where to start with setting it up, let alone using it.
There’s nowhere to hide bad form, you can’t cheat the range, and it burns your quads–a lot. But master this machine and you’ll unlock next-level quad growth, a lower-back-friendly squat alternative, and the ideal superset partner for exercises such as lunges or leg extensions.
It’s time to stop skipping the hack squat and start prioritising it in your leg day regime. From set up to mastering the perfect hack squat form, we will give you everything you need to know.
Don’t have access to a hack squat machine? No problem: We’ll also give you the best hack squat alternatives - no machine needed.
If you’re ready to gain some serious size on your thighs, stick with us and prepare for some heavy lifting 🦵.
What Is A Hack Squat?
Despite the exercise creeping up on our social feeds more frequently, the hack squat is not a new invention. In fact, it’s been around since the early 1900s as a trusted method of building strength, speed, power, and agility [1]. Its creation is credited to weightlifter and wrestler George Hackenschmidt, who lifted 187lb on his back with his knees bent. He realized the squat adaptation allowed a heavier weight to be lifted without load on the spine, which became known as the ‘Hack Squat’. Today, the hack squat machine is a staple in most bodybuilding gyms.
As an exercise, the hack squat lies somewhere between a barbell squat and a leg press—the upright body position and weight loading mimic those of a barbell squat, while the stability of the machine mimics the leg press. The hack squat is usually performed on a hack squat machine, where the lifter stands on a plate and the weight rests on their shoulders. The lifter squats down and then pushes the weight up, driving through their feet.
How To Use A Hack Squat Machine
Many gyms have a hack squat machine, which is the easiest way to set up and perform a hack squat. It can look scary and intimidating at first, but trust us, this machine is actually very safe.
Set up:
Load the machine with the desired weight (note: the hack squat alone can be heavy! If you’re new to this exercise, don’t load any weight on the hack squat machine initially until you are confident with your set up, foot position and form).
Adjust the shoulder pads if necessary (the bars should be locked in on the highest safety hook possible for your height). To do this, step onto the platform, placing your back against the backrest. Position your shoulders underneath the safety pad, and stand up and move the safety pins up and in. Stand up as tall as you can, then push the safety bars back into place by pushing them outwards as you bend your legs to move your body downwards.
Movement:
Once the machine is set to the correct height and your weight plates are loaded, it’s time to start the exercise.
Step onto the platform, positioning your feet as you would for a regular squat: feet hip width apart, toes pointing slightly out (note: If you are targeting your quads, your feet should be placed lower on the platform; for glutes, feet shoulder higher. See below).
Place your back against the backrest and hook your shoulders underneath the shoulder pads. Push through your feet, fully extending your legs. Release the safety pins and pull the safety racks inwards.
Slowly lower the weight, squatting down by bending your knees and driving them out in line with your toes. Lower as far as you can while keeping your heels in contact with the ground if you want to emphasise the quads, or down to parallel if you want to target the glutes (see below).
Pause, then reverse the movement, extending your legs and driving through your heels, until you return to the starting position. Ensure your knees do not lock out at the top.
Repeat for the desired number of reps.
Hack Squat Form
Hack Squat Feet Position
The hack squat is usually known as a quad-focused exercise. However, adjusting your foot placement and squat depth can emphasise the quads to a greater degree or turn it into a more glute-focused exercise.
Whilst no research has been done on different hack squat foot placement, studies have examined foot placement during the leg press, which could be applied to the hack squat. They found that placing the feet lower on the platform led to greater quad activation, whereas higher foot placement activated the glutes more [2]. Regarding stance width, activation was found to be just as effective during both a narrow and a wide stance [3].
Hack Squat For Quads
Choose a comfortable stance: This should usually be your regular squat stance, feet shoulder width apart, toes pointing slightly out.
Place feet low on the pad (but if you feel your heels lifting at depth, move your feet up slightly)
Sink low into your squat, aiming to get your hamstring to your calf.
Drive knees forward in line with toes.
Keep the lower back and hips in contact with the pad.
Why it works: A lower foot position reduces hip involvement and increases knee flexion, meaning the quads do more of the work.
Hack Squat For Glutes
Choose a comfortable stance: This should usually be your regular squat stance, feet shoulder width apart, toes pointing slightly out.
Place your feet higher up on the pad.
Don’t come as low: Come down so knees are at a 90-degree bend and hamstrings are parallel with the plate.
Why it works: A higher foot position increases hip flexion, which activates more glute and hamstring muscle fibers during the upward drive.
Core Engagement During Hack Squat
Whilst core engagement is required to protect the lower spine and back during the movement, it’s important to note that due to the machine's support of the upper body, core muscle activation is lower during the hack squat than during a barbell squat [4].
This allows for heavier loads to be lifted, making the hack squat well suited to those with aesthetic goals (e.g., bodybuilders who want to focus purely on leg gains).
However, if your overarching goal is performance-based (e.g., building athleticism for running, calisthenics or weightlifting), then a free weight squat (barbell or goblet squat) may be more beneficial. It provides more challenge for core stability, balance, and muscle coordination—important skills in many sports.
Hack Squat Common Mistakes Q&A
👉 ’My knees hurt when I hack squat! How do I stop this from happening?’
If your knees hurt during hack squats, it’s usually a sign that your form is off or something needs altering with your setup. The most common reasons your knees might hurt are:
Your feet are placed too low on the platform. This increases knee flexion, pushing your knees far over your toes and stressing the patellar tendon. Placing your feet higher on the platform will move some of the load towards your glutes and hamstrings.
Your knees are caving in. This puts uneven pressure on the joint and can irritate the ligaments or cartilage. Focus on driving your knees out, thinking about twisting your feet outward(like you're screwing them into the floor) without actually moving them, just as you would during a squat.
You’re going too deep. Although the aim is to get your hamstrings to your calves in the bottom position (if you’re trying to target your quads), going deeper than your flexibility will allow can lead to rounding of the lower back and lifting of the hips, which can put excessive stress on the knee joint. Only go down as far as possible while keeping your heels down, hips and back flat, and knees in line.
👉 ’I can lift more weight on one side than the other and feel one leg doing more work! How do I fix this?’
One leg doing more work is generally due to a strength imbalance or coordination issue. First, you should check your setup, ensuring both feet are placed evenly on the platform, the same distance from the edge, and at the same angle. Then, as you squat down, focus on feeling both legs working evenly. It can help to employ mind-muscle connection and slow down the reps to focus on distributing the work evenly between both legs. When you drive out of the squat, focus on pressing evenly through both heels, not letting one foot dominate.
Suppose you still feel like one leg is taking more of the workload. In that case, you should add some unilateral exercises to your routine to iron out strength imbalances, improve coordination, and teach your body to share the workload more evenly.
These could include:
Step-ups
Reverse lunges
Single-leg leg press
Single-leg Romanian deadlifts
👉 ’My heels lift at the bottom of the hack squat! Why does this happen and how can I fix it?’
This is a common hack squat form issue that could be due to poor ankle mobility, foot placement, or improper weight distribution:
Limited ankle dorsiflexion: When your ankles can't bend enough to allow your knees to travel forward, your body compensates by lifting the heels. Work on your
using exercises such as wall ankle rocks and calf stretches, particularly during warm-up before hack squats.
Feet placed too low on the platform: A low foot position forces the knees far forward over the toes, lifting the heels. Move your feet higher on the platform and focus on driving through your heels when you push out of the squat.
Weak posterior chain engagement: Not engaging your glutes and hamstrings effectively could lead to the weight shifting from your heels to your toes. Control the tempo of your hack squat, and don’t ‘bounce’ out of the bottom position, using mind-muscle connection to focus on your glutes and hamstrings engaging. You may also need to add some glute, hamstring, and core strengthening work to your routine to create a more stable posterior chain and reduce reliance on the quads.
Hack Squat Benefits
Targeted Quad Development
The fixed upright position of the hack squat ensures the quads are the primary driver on the upward phase of the movement, compared to a back squat, where work is distributed more evenly between the leg muscles. If growing your quads is your goal, then the hack squat is one of the best exercises you can do.
Provides Stability
Using a hack squat machine, the body's position is isolated, and the back is supported throughout the movement, making it more stable than a barbell squat. Not only does this make the exercise safer, but it is also a great alternative exercise for those with back pain or stability issues who cannot perform a barbell squat [5].
Better For Those With Limited Ankle Mobility
A barbell squat requires good ankle mobility to reach full depth while allowing the knee to track over the toes through a dorsiflexion movement. This can be challenging for some with limited ankle mobility. Hack squats, on the other hand, require less ankle mobility to reach full depth, as the shins stay more perpendicular to the ground. This makes it easy for those with limited ankle mobility to perform the movement correctly and work the muscles through full ROM.
How Does The Hack Squat Compare To Other Leg Exercises?
Hack Squat vs Leg Press
The most apparent difference between the leg press and hack squat is the body position - with the leg press, the lifter leans back or lies down at a 45-degree angle, pushing the weight upwards, whereas, during a hack squat, the weight rests on the lifter’s shoulders.
Other Key Differences Include:
The leg press allows one leg to be worked at a time, evening out muscular imbalances.
Most people can lift more weight during the leg press, allowing for higher muscle loading.
Hack squats are better at targeting quads, whereas the leg press is one of the best exercises for increasing overall leg strength [7].
Hack squat provides better specific training for barbell squats, as the weight is loaded onto the shoulders, rather than at the feet.
Hack Squat vs Back Squat
The most significant difference between the hack squat and barbell back squat is stability. As discussed, the hack squat holds the upper body in a fixed upright position, whereas a back squat requires a lot more core activation to safely perform the movement [8].
Other Key Differences Include:
Hack squat primarily targets the quads, whereas the back squat recruits several muscle groups in the hip, knee, and ankle joints, leading to more overall development in the lower body [9].
Barbell back squats are more complex to learn, making hack squats preferable for beginners.
Barbell back squats are more fatiguing, often requiring greater recovery time than hack squats.
Barbell back squats place more stress on the spine, which may be problematic for those with back issues.
Hack Squat vs Reverse Hack Squat
You may have seen the hack squat performed backwards, with the lifter facing the machine. Don’t worry, they aren’t performing the hack squat wrong – this is a variation of the regular machine hack squat.
Instead of honing in on quad activation, the reverse hack squat fires up the glutes and hamstrings. With the chest facing the back pad of the hack squat machine, the reverse hack squat allows the butt to be pushed back, increasing knee flexion and posterior chain activation.
Other Key Differences Include:
Reverse hack squat requires greater hip flexion, as the hips hinge to lower the weight. During the regular machine hack squat, the knees do more work.
The reverse hack squat is more transferable to front squats due to the weight's anterior loading (on the front), requiring the body to adjust form and posture similar to how it would during a front squat.
3 Hack Squat Variations
Don’t have access to a hack squat machine, but still looking to build your quads? There are several machine hack squat alternatives, so you don’t need to worry about missing out on those gains!
Barbell Hack Squat
Smith Machine Hack Squat
Landmine Hack Squat
1. Barbell Hack Squat
The most common variation of the machine hack squat is the barbell hack squat. The key difference here is that the barbell is placed behind you, and lifted from the floor, rather than the weight resting on the shoulders.
This variation adds an additional challenge of grip strength – the development of which is beneficial for many other movements including deadlifts and barbell rows. Whilst you may not be able to lift as much as you would during a machine hack squat, you should still be able to lift a significant weight during the hack squat barbell to effectively challenge the legs.
How To Perform the Barbell Hack Squat:
Stand with your feet hip-width apart, barbell behind you.
Squat down, taking the bar in an overhand grip (knuckles facing down), hands just outside of legs.
Take a deep breath in, engaging the core. Keeping a flat back and chest up, stand up, driving through the heels.
Pause at the top of the movement, squeezing your quads and glutes.
Reverse the movement, squatting back down to the starting position in a controlled manner.
Tip: Try adding elevating your heels on a plate. This will encourage a deep squat position, firing up the quads even more.
2. Smith Machine Hack Squat
The Smith Machine hack squat is a great alternative to the machine hack squat, with a similar loading (weight rests on shoulders) and a fixed bar path. If you don’t have access to a hack squat but want to focus on training your quads, give the Smith Machine hack squat a go.
How To Do The Smith Machine Hack Squat:
Set the Smith Machine bar to shoulder height.
Approach the bar and rack it on your upper back, placing your hands just outside of the shoulders. (Face in the direction that will allow you to rotate your wrists backwards to unrack the bar. Usually, this is facing outwards, away from the machine.)
Move the bar off the hooks and walk your feet out a couple of steps, so they are in front of the bar. (This is where the Smith Machine hack squat differs from a regular Smith Machine squat). Place your feet hip-width apart, toes facing forward.
Brace your core and squat down until your thighs are parallel to the floor, ensuring the lower back does not round and your knees track in line with your toes.
Pause and then push through your heels to come back up to standing.
Repeat for the prescribed number of reps.
3. Landmine Hack Squat
If you read our previous article on the Landmine Press, you’ll be familiar with the barbell landmine. Once a barbell is attached to the landmine, one side becomes anchored to the floor, whilst the other end is free-moving. This provides enough stability to safely perform a hack squat.
How To Do A Landmine Hack Squat:
Secure the barbell into the landmine attachment. If you wish, load a weight plate onto the free end of the barbell to increase the load.
Clean the barbell up onto one shoulder, then turn 180-degrees so you are facing away from the landmine, holding the end of the barbell with both hands.
Step your feet a couple of steps out in front of you, positioning your feet hip-width apart.
Squat down, pushing your hips back, keeping a flat back, upright chest, and core engaged, until your thighs are parallel to the floor.
Pause and then drive through your feet, straightening your legs until you are back at the starting position.
To ensure safe descent, turn back to face the barbell, before transitioning it from your shoulder, to between your legs, down to the floor.
As the landmine hack squat is asymmetrical (the barbell is placed on one shoulder) it’s important to maintain weight distribution throughout the movement, engaging both shoulders and keeping the torso straight. Alternate sides every set to prevent muscular imbalance.
Ready For Leg Day?
If you’re ready to build and define your quads, give the hack squat a go. For ultimate muscle gain, choose one of these exercises and perform four sets of 8-12 reps on your next leg day – just don’t blame us if you can’t walk the next day!
FAQs
What Muscles Does The Hack Squat Work?
The hack squat engages several lower body muscles, including the quads (primary target muscle), hamstrings, glutes and adductors (inner thigh). The hack squat also engages the calves, core and spinal erectors that assist as stabilizer muscles for the movement.
Foot placement and depth during hack squats can shift the emphasis towards different muscle groups, for example, placing your feet lower on the platform and squatting as low as possible while keeping your heels down reduces hip involvement and increases knee flexion, meaning the quads do more of the work. Placing your feet higher on the platform and squatting to parallel increases hip flexion, which activates more glute and hamstring muscle fibers during the upward drive.
Are Hack Squats As Good As Squats?
Hack squats aren’t a direct replacement for squats, but there are times when they can be just as good (if not better) than regular squats:
Better quad isolation: Hack squats are more quad-dominant for bodybuilders or those with specific physique goals.
Kinder on the lower back: Hack squats use a back pad to support the lower back, meaning there is less spinal loading than barbell squats. This can be better for those rehabbing or managing back pain.
Beginner-friendly: The fixed bar path of hack squats removes the need for core stability, balance, and coordination of free weight squats, making them easier to learn and safer, particularly for beginners.
However, there are times when a free weight squat is better than a hack squat:
Hack squats are less functional and don’t build real-world movement patterns, balance, stabilization, or free squats.
Hack squats require less engagement of
core stabilizers, glutes, and hamstrings
than back or front squats, meaning you miss out on full lower-body development unless you supplement with other exercises.
The fix movement path can feel awkward to some and even aggravate joints if set up incorrectly.
You should use hack squats alongside free weight squats to benefit from both exercises.
Are Hack Squats Better Than Leg Press?
Not necessarily, but they have different benefits that may suit some people better, depending on goals, anatomy, and training experience.
Both exercises effectively work the quads, but the hack squat more closely mimics the squat, whereas the leg press has less spinal load and is easier to progress with heavy loads.
Hack squats might be better if:
You want to mimic a squat without loading your spine directly.
You're focusing on quad development with more squat-like mechanics.
You want to work on knee tracking and depth in a fixed path.
You’re rehabbing and wish to limit back involvement, but still practice vertical squatting.
The leg press might be better if:
You’re dealing with lower back pain or mobility restrictions that make squatting uncomfortable.
You want to load up heavy and push volume with less technical fatigue.
You need variety in foot placement (high, low, wide) to target different muscles.
You’re training around an injury or focusing on pure hypertrophy with less joint stress.
Is Hack Squat Bad For Your Knees?
No–but it can be done with poor form or excessive weight! For example, if your feet are too low on the platform, your heels lift when you reach depth, your knees cave in, or you use too much weight.
To protect your knees during hack squats:
Place your feet slightly higher on the pad, shoulder-width apart.
Keep your heels flat and push through them throughout the movement.
Focus on knees tracking in line with toes—never let them collapse inward.
Don’t bounce out of the bottom—control the eccentric and explode up.
Warm up properly (especially quads, glutes, and ankles).
What Is The Best Stance For Hack Squats?
Hack squats are most commonly performed with a shoulder-width stance, toes slightly out, and low on the platform (or as low as you can go without your heels lifting). This stance emphasises the quads, which is the classic way of doing the exercise. However, hack squats can also be performed with a wider stance, higher on the platform, to emphasise the glutes and hamstrings.
That being said, individuals will likely need to make adjustments based on their anatomy: Some lifters, especially taller ones or those with longer femurs, prefer a slightly wider stance with toes turned out for better depth and heel contact. Those with limited ankle mobility will prefer a higher and wider stance, reducing how far their knees need to travel forward and easing pressure on the ankles.
If you’re new to hack squats, perform the exercise without external weight first so you can experiment with different stances and find what works for you.
References:
Schwarz, N.A. et al. (2019) A comparison of machine versus free-weight squats for the enhancement of lower-body power, speed, and change-of-direction ability during an initial training phase of recreationally-active women, Sports (Basel, Switzerland). Available at: https://pubmed.ncbi.nlm.nih.gov/31574918.
Martín-Fuentes , I., Oliva-Lozano, J.M. and Muyor, J.M. (2020) Muscle activation and kinematic analysis during the inclined leg press exercise in young females, International journal of environmental research and public health. Available at: https://pubmed.ncbi.nlm.nih.gov/33238589.
Martín-Fuentes, I., Oliva-Lozano, J.M. and Muyor, J.M. (2020) Evaluation of the lower limb muscles’ electromyographic activity during the leg press exercise and its variants: A systematic review, MDPI. Available at: https://www.mdpi.com/1660-4601/17/13/4626.
Clark, D.R., Hunter, A.M. and Lambert, M.I. (2019) Trunk muscle activation in the back and hack squat at the same relative loads, Journal of strength and conditioning research. Available at: https://pubmed.ncbi.nlm.nih.gov/28704312/.
Da Silva, E.M. (2008) Analysis of Muscle Activation During Different Leg Press Exercises at Submaximum Effort Levels. Available at: https://journals.lww.com/nsca-jscr/pages/articleviewer.aspx?year=2008&issue=07000&article=00005&type=Fulltex.
Clark, D.R., Hunter, A.M. and Lambert, M.I. (2019) Trunk muscle activation in the back and hack squat at the same relative loads, Journal of strength and conditioning research. Available at: https://pubmed.ncbi.nlm.nih.gov/28704312/.
Martín-Fuentes , I., Oliva-Lozano, J.M. and Muyor, J.M. (2020) Muscle activation and kinematic analysis during the inclined leg press exercise in young females, International journal of environmental research and public health. Available at: https://pubmed.ncbi.nlm.nih.gov/33238589.
Gullett, J.C. et al. (2009) A biomechanical comparison of back and front squats in healthy trained individuals, Journal of strength and conditioning research. Available at: https://pubmed.ncbi.nlm.nih.gov/19002072/.
Clark, D.R., Lambert, M.I. and Hunter, A.M. (2012). Muscle Activation in the Loaded Free Barbell Squat. Journal of Strength and Conditioning Research, 26(4), pp.1169–1178. doi:https://doi.org/10.1519/jsc.0b013e31822d533d.
