Hack Squat

Powerlifting is based on three big compound lifts; the squat, deadlift, and bench. Whilst these should form the base of most well-organized programs, several variations have useful training applications.

If we had to list the best quad-building exercises, the hack squat variation would be near the top. The concept of the hack squat is simple; move a loaded carriage up and down two rails. Despite this, it offers many versatile uses when programmed correctly.

We’ve discussed the hack squat in detail below including the form, programming, muscles worked, and who should perform them.

How To Do

  1. Start by standing in front of the hack squat machine. Ensure the weight plates are correctly loaded onto the bars under the weight sled.
  2. Step onto the platform, placing your back and shoulders against the pads. Ensure your head is facing forward with your chest out.
  3. Stand with your feet shoulder-width apart and pointing slightly out. They should be flat against the platform.
  4. Take a deep breath in to engage your core. Perform hip and knee flexion until your body lowers down to a 90-degree angle. Imagine sitting in a chair with a weight on your back. 
  5. Pause briefly at the bottom position. Exhale and push through your heels to extend your legs. Keep a neutral back position with your chest up.

Tips From Expert

  • Avoid rounding your back - Engage your core and keep your back firmly against the back pad with your head facing forward.
  • Don’t use too much momentum - When you lower the sled down, avoid bouncing at the bottom position. Instead, pause briefly and focus on the mind-muscle connection.
  • Ensure your heels stay on the platform - Ensure your feet are shoulder-width apart firmly against the platform. If you can't perform a rep without your heels lifting, change your foot position.

Optimal Sets and Reps

When using the hack squat machine, use the programming table below as a general guide. These can be followed according to your exercise goals

Training Type Sets Reps
Strength Training 5 5
Hypertrophy 3–4 8–10
Endurance Training 3–4 12–20
Power Training 3–5 3–5

How to Put in Your Workout Split

The hack squat is a versatile lower-body exercise. It can be programmed into an exercise routine for a number of workout goals. 

Whether you're looking to build muscle, develop strength, or work around an injury, the hack squat offers a great option. The key difference is in the way it's programmed. 

For strength and hypertrophy work, several different workout splits can be used:

  • Push/ pull - For a push/ pull split, look to program hack squats on your push days. Include them as one of your primary movements with one or two isolation exercises. 
  • Bro Split - Program the hack squat on your lower body days when performing the bro split. Pair them with some isolation exercises such as lying leg curls and calf raises. 
  • Total body - As you’ll be working your full body every day, hack squats can be programmed as needed. Start with large compound lifts and program hack squats just after them or as a stand-alone movement. 

If your main goal is strength development, you’ll want to program the hack squat after your main movement patterns. Doing this gives you more energy for the specific strength application work on your squats, deadlifts, and bench. Following this, hack squats can be programmed between these and the isolation-type exercises.

Primary Muscle Groups

Gluteus

Large, superficial muscles located at your buttocks just below your lower back area.

Quadriceps

Muscles located at the front portion of your upper legs, below your pelvis and above your knees. Consists of four parts.

When performing machine hack squats, your quadriceps and gluteus maximus are the primary movers. They work alongside your secondary movers to perform the hack squat correctly.

The hack squat machine angle and fixed movement path act as strong stabilizers. The degree of stabilization depends on the machine angle, with a 30-degree angle offering the most amount.

Effect On Quadriceps

The angled position of the hack squat machine placed a greater emphasis on your anterior chain muscles. At the front of your thighs, your quadriceps consist of four muscle groups. These are your vastus lateralis, vastus intermedius, vastus medialis, and rectus femoris.

Your quad muscles are primarily responsible for extending your knees and flexing your hips. During the hack squat, these are the main movement patterns that make your quads the primary movers.

Effect On Gluteus Maximus

Your gluteal muscles are three muscle groups that make up your buttocks. These are your gluteus maximus, gluteus medius, and gluteus minimus. Your gluteus maximus is the biggest and most superficial of the three muscles. 

During the machine hack squat, your gluteus maximus muscles extend your hips. They’re primarily used once you hit the bottom position to help you stand up again. 

The hack squat machine uses a bigger hip extension motion compared to traditional squats. This results in more glute activation.

Secondary Muscle Groups

Hamstrings

Muscles located at the back of your upper leg, below your glutes and above your calves. Consists of three muscles.

Gastrocnemius

Muscles located at the back of your lower leg and consists of your calf. Starts just behind your knee and extends to your ankle.

Soleus

Muscles located behind your gastrocnemius sitting slightly deeper. Runs down your leg and connects with the gastrocnemius to make your Achilles tendon.

Erector Spinae

Muscles that span the entire length of your spine on either side.

Effect On Hamstrings

Your hamstrings are located at the back of your legs below your buttocks. They consist of three muscle groups. These are your semimembranosus, semitendinosus, and bicep femoris.

The primary function of the hamstrings is to extend your hips and flex your knee joints. During the machine hack squat, they work as a secondary mover alongside your quads and glutes using the same movements.

They work synergistically with your glutes, helping to stabilize them during the movement. The more you move your feet forward during the machine hack squat, the bigger emphasis you put on your hamstrings.

Effect On Hip Adductors

Your hip adductors are located at the medial compartment of your thigh. They consist of four muscle groups. These are your adductor longus, adductor brevis, adductor magnus, and gracilis.

The primary function of your hip adductor muscles is to move your legs closer to the midline of your body. During a machine hack squat, your hip adductors help with hip extension to get up from the seated position.

Effect On Gastrocnemius and Soleus

Your calf muscles are located at the back of your lower leg. They consist of two muscle groups; your gastrocnemius and soleus. 

Your gastrocnemius is involved in knee flexion and plantarflexion while your soleus can only perform plantarflexion. This means they help to point your toes and push off the ground. 

During the machine hack squat, they act as secondary movers during the downward phase. Both calf muscles may also be somewhat activated when pushing off the platform.

Effect On Erector Spinae

Your erector spinae spans the full length of your vertebrae column from your skull to your pelvis. They are made up of three parts which are your spinalis, longissimus, and iliocostalis. Each of these muscles also split into three smaller muscles, making nine.

Their main functions are to produce back extension and lateral back flexion. In the hack squat, your erector spinae mainly functions alongside your other trunk muscles to maintain a compact lifting position.

Due to the fixed sled position, hack squats place less load on your erector spinae. This makes them great for those working around lower back injuries.

Equipment

Hack Squat Machine

Hack Squat Machine

This allows you to perform controlled squats without needing to focus on stability, providing a good progression exercise. Ensure your back is firmly against the back pad.

Alternatives

Exercises that target the same primary muscle groups and require the different equipment.

Bodyweight Squats

Squat to Jumping Jack

Goblet Squats

Chair Pose

Who Should Do?

The versatile nature of the machine hack squat makes it suitable for a wide range of people. Here are some of them in more depth.

Beginners

If you’re a beginner, the hack squat is a great way to learn the proper squatting form. The fixed sled position helps to keep your torso up while focusing on your head and chest positions. 

With less lumbar spine load, the machine hack squat provides a safer way to learn before progressing the load. You can use the sled, progress the weight, and then try traditional squats.

Alongside this, the hack squat machine safety catches offer a good safety mechanism if you fail a repetition.

Powerlifters

For powerlifting training, most of the focus will be on performance in the squat, deadlift, and bench press. Hack squats provide an excellent compound exercise for lower body strength, especially in the bottom squat position. 

Hack squats are a great way to improve your strength performance when programmed correctly after your main lifts.

Bodybuilders

For muscle hypertrophy to occur, you need a suitable exercise stimulus. The angled sled and platform positions place most of the stress onto your quadriceps. This makes the hack squat machine a great way to isolate your quads. 

The hack squat machine allows easy weight adjustments. Hook in the safety pins and slide the plates off. This makes it easy to perform giant sets for bodybuilding-style training where you perform multiple ascending sets in succession.

Alongside this, partial reps using a smaller range of motion can be done by stopping halfway down. Pause reps where you pause at the bottom hack position are also easy to perform.

Who Should Not Do?

As with any exercise, certain populations should avoid the hack squat. This is usually determined by the loading and movement patterns.

People With Knee Injuries

If you suffer from a knee extensor injury, exercises that involve knee extension should be avoided. The same goes for common knee injuries such as fractures, dislocations, tears, and sprains. 

In these cases, the focus should be on rehabilitation exercises to strengthen the surrounding structures. Weight-bearing exercise should only start again after consultation with a physical therapist.

People With Mobility Issues

The hack squat is a beginner-friendly movement that’s easy to learn. However, the large amount of hip and knee flexion required may make them unsuitable for those with mobility issues. 

In this case, the main focus should be on mobility work before hack squats can be performed.

Benefits Of The Hack Squat

When performed correctly, hack squats have several benefits. Let’s address some of the main ones in more detail.

Excellent Quad Hypertrophy

Hack squats provide an excellent way to isolate your quad muscles. When performed using the correct form, the fixed sled position makes it harder to deviate from the correct lifting position. 

This limits the involvement of other muscles, making them a great hypertrophy exercise. 
Furthermore, the fixed movement pattern in the hack squat makes it easier to get into a deeper squat position. Squatting to full depth is a main determinant of hypertrophy, making the machine hack squats a good exercise.

Less Lumbar Spine Loading

The fixed movement pattern combined with the angled sled reduces the amount of lumbar load compared to traditional squats. If you’re suffering from lower back issues, hack squats provide an excellent option.

Improved Functional Performance

To perform a hack squat, you need to use a wider hip flexion range. This makes it a great functional exercise to improve performance in sporting events requiring similar movement patterns. Examples would be jumping, changing direction, and sprinting. 

Furthermore, the movement pattern translates well into daily activities. Most movements require some degree of hip and knee flexion. Examples include picking up the shopping bags and getting something from a bottom cupboard.

Frequently Asked Questions

Are hack squats better than squats?

Hack squats and traditional squats are both great lower-body exercises. However, they may be better for quad development and reduce lower back stress due to the lifting position.

Why is hack squat more difficult?

To perform a hack squat correctly, your body is kept in a fixed position. Therefore, it’s less forgiving than a normal squat and requires good quad and glute strength.

What are the mistakes for hack squats?

Common hack squat mistakes include bringing your heels off the ground, using excessive momentum, and rounding your lower back.

Is the hack squat better than the leg press?

Both exercises are great for lower body development but differ in the movement pattern and muscle recruitment. Hacks squats are better for quad development and functional movement progression.

Resources

  1. Bordoni, B. and Varacallo, M. (2023). Anatomy, Bony Pelvis and Lower Limb: Thigh Quadriceps Muscle. [online] Nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK513334/ [Accessed 14 Jun. 2024].
  2. ‌Adel Elzanie and Borger, J. (2023). Anatomy, Bony Pelvis and Lower Limb, Gluteus Maximus Muscle. [online] Nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK538193/ [Accessed 14 Jun. 2024].
  3. ‌None Krzysztofik, Wilk, N., None Wojdała and None Gołaś (2019). Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods. International journal of environmental research and public health/International journal of environmental research and public health, [online] 16(24), pp.4897–4897. doi:https://doi.org/10.3390/ijerph16244897.
  4. ‌Apseloff, N., Guttu Maskalo, Findlay, G. and Hughes, J.D. (2024). Extensor Mechanism Injuries: is return to sport feasible? Operative techniques in sports medicine, [online] pp.151090–151090. doi:https://doi.org/10.1016/j.otsm.2024.151090.
  5. ‌Ribeiro, A.S., Santos, E.D., João Pedro Nunes, Nascimento, M.A., Ágatha Graça, Bezerra, E.S. and Mayhew, J.L. (2022). A Brief Review on the Effects of the Squat Exercise on Lower-Limb Muscle Hypertrophy. Strength and conditioning journal, [online] 45(1), pp.58–66. doi:https://doi.org/10.1519/ssc.0000000000000709.
  6. ‌Deniz, E. and Yavuz Hasan Ulas (2019). Evaluation of Muscle Activities During Different Squat Variations Using Electromyography Signals. Advances in intelligent systems and computing, [online] pp.859–865. doi:https://doi.org/10.1007/978-3-030-35249-3_114.
  7. Schwarz, N., Harper, S., Waldhelm, A., McKinley-Barnard, S., Holden, S. and Kovaleski, J. (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, [online] 7(10), pp.215–215. doi:https://doi.org/10.3390/sports7100215.