Hack Squat vs Leg Extension: Which is Best for Your Quads?

Written by the Boostcamp staff
Feb 6,2024|15 min| 2744

Hack Squat vs Leg Extension: The Ultimate Comparison

When it comes to the best leg exercises and adding inches to those tree trunks, there are a ton to choose from such as barbell squats or the leg press, dumbbell movements, or even bodyweight exercises. But when it comes to quadriceps development specifically, two very popular exercises often spark a heated debate: the hack squat vs. leg extension. Both exercises claim to be the best quad exercise, but which one truly reigns supreme?

In this article, we'll delve into the details of each exercise, discuss the benefits and drawbacks, and provide you with the knowledge needed to decide which is best for your workout routine.

Table of Contents

  1. Introduction

  2. Hack Squat: What it is and How to Do It

  3. Leg Extension: What it is and How to Do It

  4. The Benefits of Hack Squat vs. Leg Extension

  5. Pros and Cons of Each Exercise

  6. Importance in a Workout Program

  7. FAQ: Top 10 Most Common Questions

  8. Conclusion: Choosing the Best Quad Exercise for You

Hack Squat: What it is and How to Do It

The hack squat is a compound exercise which is relatively similar to the barbell squat that primarily targets the quadriceps but also engages the glutes, some hamstring engagement, and calves as secondary muscles. The movement is performed using a hack squat machine, which provides support and stability throughout the exercise. It is a favorite of bodybuilder Tom Platz, who had some of the best legs on the planet.

How to Do Hack Squats: Muscles Worked & Benefits – StrengthLog

Image source: StrengthLog

How to Perform a Hack Squat

  1. Adjust the hack squat machine to fit your body, positioning your shoulders and back against the pads.

  2. Position your feet shoulder-width apart with toes pointing slightly outwards.

  3. Lower your body by bending your knees, keeping your chest up and back straight.

  4. Once you reach a 90-degree angle at your knees, push through your heels to return to the starting position.

You can also angle your feet in different positions to focus on different muscles in the legs, for example putting your feet closer together would bias the quads slightly more. You also can work one leg at a time on the hack squat, putting one foot back and one foot up, and all of the pressure would be on your front knee. Then, your back foot should have the heel up with your weight on the ball of the foot, and your back knee would drop down and touch the foot pad, simulating a split squat or walking lunges type of movement and really putting an emphasis on the quads. This exercise is similar to a dumbbell split squat, where the weight is on your front foot. By incorporating the front foot in the hack squat, you can target your quads even more effectively on an elevated surface.

Why Do Hack Squats?

Hack squats are a great addition to your workout routine because they effectively target the quads while also working the other muscles in your lower body, making them a great exercise for the overall development of your leg muscles and for building muscle mass. This compound exercise helps to increase strength and improve overall lower body functionality. Hack squats are especially great if you are unable to do barbell squats, maybe due to injury or other circumstances, but the hack squat allows you to still get a great workout in and really focus on the mind-muscle connection.

Leg Extension: What it is and How to Do It

The leg extension is an isolation exercise that specifically targets the quadriceps. This exercise is performed using a leg extension machine, which isolates the quads by limiting the involvement of other muscle groups.

How to Do Leg Extension: Muscles Worked & Proper Form – StrengthLog

Image source: StrengthLog

How To Perform a Leg Extension

  1. Adjust the leg extension machine to fit your body, sitting in an upright position with your back up against the pad, positioning your ankles behind the padded roller.

  2. Sit with your back against the backrest and grip the handles for stability.

  3. Extend your legs until they are straight, squeezing your quads at the top of the movement.

  4. Slowly lower your legs back to the starting position, maintaining control throughout.

Why Do Leg Extensions?

Leg extensions are an effective way to isolate and target the quadriceps, including the rectus femoris. This exercise can help increase quad strength, muscle definition, and improve knee stability and mobility. You also are able to easily incorporate things like drop sets with the leg extension, and you can really overload the muscles in the quads with this piece of equipment. The leg extension also helps with knee flexion, which can transfer over to your mobility and help soothe knee pain. It can help to strengthen the knees, as this is technically a "knee extension" exercise. Having strong quads is also essential for better hip flexion and knee stability, allowing you to walk, run, jump, squat, and climb stairs with greater ease. In fact, many exercises that focus on this muscle group can be done with just your body weight.

The Benefits of Hack Squat vs. Leg Extension

Now, when it comes to these two exercises, both hack squats and leg extensions offer unique benefits for your overall quadriceps development. Hack squats are better suited for total lower body development, as even though you can switch up your stance to bias the different muscles in the legs, they are still compound exercise that engage multiple muscle groups. Leg extensions, on the other hand, totally isolate the quad muscles, making them perfect for targeted muscle development.

Pros of Hack Squat

  • Focuses on quadriceps development, but also hits hamstrings

  • Builds overall lower body strength

  • Functional exercise for athletics

  • Can be a good squat alternative if you have a back injury or are unable to squat for another reason

Cons of Hack Squat

  • Requires access to a hack squat machine

  • May put some strain on the lower back

Pros of Leg Extension

  • Completely isolates quadriceps development

  • Improves knee stability

  • Easily adjustable resistance

Cons of Leg Extension

  • Requires access to a leg extension machine

  • May put more stress on the knees

Importance of Hack Squats and Leg Extensions in a Workout Program

Image courtesy of Instagram (tomplatz)

Both exercises can play an essential role in a well-rounded workout program. Whether you are following a push pull legs split, or an upper lower split, or another type of split, incorporating both hack squats and leg extensions into your routine can help ensure comprehensive quadriceps development while also promoting overall lower body strength and functionality. But before you go jumping into sporadic and unorganized training, you may want to check out some workout programs.

Depending on your goals, you may choose to prioritize one exercise over the other, and there is nothing wrong with that. For those looking to build overall leg strength and engage multiple muscle groups, hack squats might be the better option. Conversely, if you're aiming to isolate and target the quads specifically, leg extensions could be the right choice.

FAQ: Top 10 Most Common Questions

Which exercise is better for overall quadriceps development?

Both exercises help to contribute to your quad development, but hack squats may offer more comprehensive development due to their compound nature, meaning you can overload the quads a little bit more than you would with a leg extension. Putting too much weight on a leg extension risks injury, as a lot of that weight is on the knees.

Are hack squats or leg extensions safer?

Both exercises, when performed correctly, are safe for your knees. This means with proper form, and not too much weight, you should not be at risk of an injury or anything like that. However, hack squats may place strain on the lower back, while leg extensions tend to put a little bit more stress on the knee joint. Always use proper form and consult with a trainer if needed.

Can I do both exercises in the same workout?

Yes, incorporating both exercises in your workout can help ensure comprehensive quad development and overall lower body strength. For example, you may use leg extensions as a warmup exercise while using hack squats as the main compound. Or you start off with the hack squat and finish with sets of the leg extension until failure. It's important to note that a well-rounded strength training routine will incorporate not only quadriceps muscles, glute exercises, and hamstring exercises, but also exercises that require greater balance and coordination, such as the dumbbell lunge, to thoroughly work both sides of your legs.

Which exercise is better for increasing leg size and strength?

Both exercises can contribute to leg size and strength, which means that they would be beneficial for strength athletes as well as bodybuilders who are looking to improve their physique. However, hack squats, as a compound exercise, might lead to greater overall muscle growth as well as strength gains than the leg extension would.

Are hack squats suitable for beginners?

Yes, hack squats are suitable for beginners, as long as you focus on form before weight. The hack squat machine provides stability and support, making it an excellent choice for those new to weight training.

Can I perform leg extensions without a machine?

Although leg extensions are typically performed on a machine, you can perform a similar movement using ankle weights or resistance bands.

How often should I perform hack squats and leg extensions?

This depends on your workout routine and goals. Generally, training legs 2-3 times per week with a mix of compound and isolation exercises is recommended for balanced development.

How many sets and reps should I perform for each exercise?

Aim for 3-4 sets of 8-12 reps for both exercises. Adjust the resistance to ensure you're working within this rep range and progressively increasing the weight over time.

Can I replace hack squats with regular squats?

Yes, regular squats can be a suitable alternative to hack squats. However, they may place more emphasis on the glutes and hamstrings, rather than solely targeting the quads.

Can I replace leg extensions with lunges or step-ups?

While lunges and step-ups are great exercises for overall leg development, they do not isolate the quads as effectively as leg extensions.

Conclusion: Choosing the Best Quad Exercise for You

Ultimately, the best quad exercise for you will depend on your goals, preferences, abilities, and access to equipment. Both hack squats and leg extensions offer unique benefits for quadriceps development, so incorporating both into your workout routine can lead to well-rounded progress. Always prioritize proper form and technique to maximize results and minimize the risk of injury. Adding the keyword "best exercises" enhances the paragraph by emphasizing the importance of selecting the most effective exercises for quad development. It aligns with the blog title "Hack Squat vs Leg Extension: The Ultimate Comparison" and the H2 "Conclusion: Choosing the Best Quad Exercise for You." The keyword reinforces the idea that choosing the right exercises is crucial for achieving optimal results.

Where to Find Workout

When it comes to finding some quality workout routines that help with your leg days and really forward your progress, check out the Boostcamp App for some great programs. Whether that is push pull legs or upper lower or whatever else you may be trying to do, Boostcamp has something for you. You would want to find a program that caters to your needs, gives you good accessories to do, and guides you in the right direction, making sure that you are making the most gains. If you are looking to stay on track and continue with linear progression, then finding a good workout program is the key, and Boostcamp is the place to go.

Also, be sure to follow Boostcamp on Instagram and subscribe on YouTube!