Pop your head into any commercial gym, and you’ll almost certainly see lifters developing their legs using the hack squat and the leg press.
So, what are the differences between the hack squat vs leg press? Hack squats are loaded on the shoulders, with the lifter having to squat down and stand up to perform the exercise. The leg presses are loaded via a platform that the lifter pushes away while laying down. Both primarily target the quads, with a secondary emphasis placed on the glutes muscles.
I’ll thoroughly explain the hack squat and leg press in detail down below, including how, why, and when to program in each of these exercises into your training regimen. Finally, I’ll instruct you on how to perform each movement correctly while keeping in mind each of their respective pros and cons, and how to avoid common mistakes.
The Differences Between a Hack Squat and Leg Press
At first glance, the hack squat and leg press appear to be similar movements with respect to the muscle groups they target, but there are some key differences that you should understand if you want to develop the muscle and strength of your legs.
While these exercises are comparable, they aren’t interchangeable.
It’s true, they both target the quads and glutes. However, they each apply load to the lifter differently and have unique supporting muscle groups that assist during the exercise.
There are 4 main differences between the hack squat and leg press:
- Weighted Used
- Muscles Worked
The hack squat machine consists of a backrest and shoulder pad assembly that slides up and down a set of tracks on either side of the machine with a platform at the bottom. The machine keeps the lifter leaning backwards at a 45 degree angle throughout the movement.
On the flip side, the leg press has a couple different machine variations. The less common version places the lifter in a seated position with their feet directly in front of them, requiring the lifter to push the platform horizontally away from them.
The more common leg press machine has the lifter laying down against a back pad, with their legs angled upwards at a 45 degree angle — pushing the platform away to perform the exercise.
In the hack squat and leg press, the lifter is leaning back at a 45 degree angle and laying down with their legs up at 45 degrees, respectively. Since the lifter and machine also move horizontally during these exercises, there is a significant change in the biomechanics of the movements.
Consider this: the lifter is fighting entirely against gravity when performing a squat or a bench press. In both of these cases, the bar is (ideally) moving straight down and directly back upwards.
However, the lifter is not only moving in a vertical plane during the hack squat and the leg press. There is also some horizontal movement of the lifter or load throughout these movements. Because of this, the machines in both of these exercises are supporting a portion of the weight loaded and higher weights can be lifted as a result.
3. Weight Used
In the hack squat, the load is supported on the lifter’s shoulders. While there’s also a mix of vertical and horizontal travel of the lifter during this exercise, the weight is still loaded axially (on the back).
In turn, the weights that can be lifted in the hack squat will be greater than those lifted in the back squat. That said, the axial load supported by the lifter must not overwhelm the strength of their torso musculature and this presents a potential limiting factor.
On the other hand, the leg press does not present this problem at all as the load is entirely supported by the legs. Since the torso musculature does not present a limiting factor whatsoever, significantly higher loads can be lifted in the leg press.
4. Muscles Worked
The hack squat and the leg press predominantly target the quads and glutes. In both movements, the hamstrings and calves are also slightly active to assist with hip and knee extension, respectively.
However, the abdominals and spinal erectors (back muscles) are working harder during the hack squat due to the axial loading demands placed on the torso muscles.
The hack squat is a machine-based compound exercise that targets the quads and glutes, and closely mimics the back squat due to the axial loading present (i.e. the load is on the back).
How To Do a Hack Squat
Here’s how to perform a hack squat:
- Step into the footprint of the machine
- Place your shoulders against the shoulder pads
- Set your feet in your regular squat stance
- When ready, stand up and disengage the stoppers
- Put your hands on the hand grips by your shoulders
- Descend by bending at your knees
- Stop once you’ve reached parallel or slightly below
- Push the platform away to stand up
- When your set is finished, re-engage the stoppers
Looking for an alternative to the hack squat? I wrote an article on the 9 Best Hack Squat Alternatives.
Technique Tips For a Hack Squat
Here are some hack squat tips to help you with your technique:
- Experiment with different rep ranges. As a compound exercise using multiple muscle groups, you’ll benefit most from the hack squat by loading it in the rep range that is most conducive to your goals. Sticking in the 3-8 rep range will likely give you the greatest strength gains, and the +8 rep range will probably give you a greater hypertrophy stimulus.
- Want to emphasize your hamstrings more? Place your feet higher up on the platform with a wide stance, and really push your knees out as you’re performing the exercise. This stance won’t let your knees travel as far forward as they would normally, reducing the demand on your quads and shifting it to your hamstrings instead.
- Want to focus more on your glutes? Put on a glute loop or glute band (click to check today’s price) and place your feet in a wide stance on the platform. As you perform the movement, you’ll have to drive your knees out against the band to avoid having them collapse in — making your glutes work overtime.
Common Mistakes When Doing a Hack Squat
The most common faults in the hack squat are:
- Not having a standardized range of motion. Ensuring all reps are brought to the same depth is important, in order to apply proper progressive overload . To facilitate this, you can either slow down a bit at the bottom or perform a pause at the bottom of each rep to ensure consistency in your range of motion.
- Going too low. Yes, deep reps will help build your quads but you don’t want your heels to lift up off the platform in order to make that happen. The key is to descend as low as you can while maintaining full contact with your heels on the platform. Read my tips on how to squat deeper.
- Resting too long at the top. It’s common for lifters to bang out the majority of the reps for their set, then begin taking extended breaks at the top with their knees locked. Doing this too often makes it more difficult to compare your sets, as the tension is shifted off your quads when your knees are fully extended.
Bonus tip: If you also find your heels rise when you perform the back squat, then check out my article on How To Fix Heel Rising During Squats (7 Tips).
Muscles Used: Hack Squat
The muscles used in the hack squat are the:
- Spinal erectors (back muscles)
The hack squat requires a significant amount of knee and hip flexion (bending). These actions require the quads and glutes to fire in order for the lifter to stand up.
If the lifter descends below parallel, the adductors will assist greatly to help with hip extension (straightening). The calves will also be recruited more in this position to assist with ankle and knee extension.
Finally, the abdominals and spinal erectors are contributing slightly to maintain the integrity of the torso throughout the exercise.
I wrote a full guide on the muscles used in the squat and different variations of the squat.
Benefits of The Hack Squat
Some of the benefits of the hack squat are:
- Developing a strong pair of quads is extremely helpful to your performance in the back squat, as they’re often the limiting factor for most lifters
- If you have a back injury that necessitates less spinal loading, then the hack squat is probably the right choice. While it doesn’t remove axial loading entirely, it certainly reduces it.
Cons of The Hack Squat
Some of the cons of the hack squat are:
- You may feel discomfort in your shoulders. Depending on the weight you’ve loaded on the machine and design of the pads, you might feel an excessive amount of pressure and/or discomfort.
- Since it doesn’t entirely eliminate spinal loading, those with sensitive backs might not be able to perform the hack squat pain-free. Definitely try it first, before loading on any weight if this situation applies to you.
The leg press is a machine based exercise that works the quads and glutes with minimal demand placed on the upper body.
How To Do a Leg Press
Here’s how to set up a leg press:
- Lay down on the machine and put your feet on the platform
- Set your feet in the same position as your squat stance
- When ready, push the platform to straighten your legs
- Disengage the safety catches
- Bend at your knees to lower the platform towards you
- Stop once your thighs are at or below parallel
- Push the platform away and back to the starting position
Looking for an alternative to the leg press? I wrote an article on the 9 Best Leg Press Alternatives.
Technique Tips For a Leg Press
Here are some leg press tips to help you with your technique:
- Be open-minded in trying different foot placements. Most lifters will place their feet in their usual squat stance, and this is probably the best to start with. However, you need to be willing to adjust your stance width and toe angle if you don’t find your original stance comfortable. You might just find that a completely different stance feels stronger for you.
- Want to hit your quads more? Take a narrower stance and place your feet lower on the platform. While this will require decent ankle mobility, it also targets your quads more due to the greater amount of forward knee travel.
Bonus tip: If you want to hit your quads more but can’t get deep enough due to less mobile ankles, throw on a pair of squat shoes. The raised heel will assist in letting your knees travel forward and will emphasize your quads more.
Common Mistakes When Doing a Leg Press
The most common faults in the leg press are:
- Not going low enough. To maximize the development of your quads, you want to encourage lots of knee flexion (bending) by going as deep as possible with your reps. Ensure that you at least get your thighs to parallel or (preferably) below parallel.
- Setting the pad angle too high. Having the back pad angled too high might feel good at first, because you can lift more weight as the range of motion is reduced. However, the shortened distance that the platform must travel means that you end up working your quads less and your lower back will be more likely to round.
- Having your lower back round at the bottom. When your low back rounds, it’s usually in an attempt to sink your reps deeper. Since most lifters use the leg press to emphasize their quads, feeling this exercise in your posterior chain (hamstrings, glutes, low back) means the main purpose has been missed.
I wrote another guide comparing the leg press vs squat, where I explain you might not need to do both exercises.
Muscles Used: Leg Press
The muscles used in the leg press are the:
The high degree of knee and hip flexion (bending) that happens in the leg press makes the quads and glutes the main movers in this exercise.
When below parallel, the adductors kick in significantly more to help the lifter extend (straighten) their hips on the ascent. Lastly, the calves also assist to a small degree in order to extend the ankles and knee.
Benefits of The Leg Press
Some of the benefits of the leg press are:
- Building a muscular set of quads and glutes will give you a thicker-looking lower body, making your waist appear narrower. In addition to wide shoulders, this will give you the sought after “X-frame” athletic look
- Strong knee extensors (quads) are integral to being able to stand up during the back squat. Considering that many lifters have a sticking point just above parallel, having strong quads will assist you in maintaining a high velocity out of the bottom of the squat — increasing your odds of finishing the lift. This is also one of the reasons why I recommended it as one of the best exercises to increase deadlift strength.
Cons of The Leg Press
Some of the cons of the leg press are:
- You may hear strange sounds in your knees. Sometimes, lifters experience “clicking” or “popping” sensations in their knees during the leg press. Don’t worry — it’s likely nothing to be concerned about.
- Due to the design of the machine and your body’s position during the exercise, the leg press is less specific to the back squat when compared to the hack squat. If specificity is important to you, then the leg press might not be the best choice.
Bonus tip: Many lifters experience clicking and popping noises while they lift — this phenomenon is called crepitus. It’s usually harmless and rarely is it ever painful. If it annoys you on most reps (or every one), try out different stance widths and toe angles to see if it goes away.
Deciding whether to perform the hack squat or leg press will depend mostly on your overarching training goal.
Hack squats are a better choice if you want an exercise that is more specific to the back squat, or you simply prefer this machine to the leg press.
Leg presses are a better choice if you want to avoid spinal loading entirely, remove any trunk and/or upper body musculature from assisting, or you just enjoy this exercise more than hack squats.
Ultimately, neither exercise has an inherent advantage over the other. It simply depends on which one will match your goal and training preferences the most.