Smith Machine Hack Squat: The Hack to Grow Quads Fast

Among the wrong crowd, Smith machines can be controversial.

Whether you love them or hate them, the Smith machine is one of the most common machines you’ll see in commercial gyms.

And even if you’re on team hater and can’t envision yourself hopping on the Smith machine for a set or two, it’s worth understanding how these machines work.

If you want to grow your quadriceps and train for bigger legs, the Smith machine may actually be one of the best tools you can keep in your arsenal.

Here we’ll explain what impact Smith machines have on targeted quad growth and see whether they’re a better alternative than barbell back squats when it comes to getting stronger quads.

How Do Smith Machines Work?

The Smith machine is named after Rudy Smith. It was in his gym that this machine first rose to prominence, pioneered by American fitness coach Jack LaLanne.

This leg workout machine is designed with a straight path of motion in mind. Smith machines have a barbell attachment that moves straight up and down.

You can do bench presses, squats, deadlifts and more as Smith machine workouts.

There is some evidence to show that the Smith machine may not activate your muscles as effectively as free weight training.

In exercises like the bench press, at least, a comparison of muscle activation between a Smith machine and free weights showed electromyography testing indicates muscle fibers activating more readily while working with free weights.

There are specific cases, though, where working with a Smith machine for your hack squats may be the best option.

First, let’s take a moment to understand which muscles are working in your body with a Smith machine hack squat.

Hack Squat— Muscles Worked

If you’re researching the hack squat machine, you may wonder what makes it different than squatting with a barbell.

Hack squats target your quadriceps muscles. Although they do work the other muscles in your legs, the hack squat is a great way to train if you’re hoping to isolate your quads.

During hack squats, the working muscles include:

Quadriceps

Your quadriceps femoris muscles (“quads”) flex your knees. When you get to the bottom of your squats, you’ll need a deep bend in the knees to help your body descend into the squat. Engaging your quadriceps will help you get there, so it’s important to make sure they’re strong.

Hamstrings

The hamstrings sit on the backs of your thighs. These muscles extend your hips at the top of a squat. They also help with knee flexion when you descend. This makes hamstrings an integral part of your squat. Always stretch your hamstrings after you squat. It’s a good idea to warm them up too.

Active workouts like high knees or leg swings will help prepare these leg muscles for healthy hack squats. Many people have tight hamstring muscles due to increasingly sedentary lifestyles. The effect of hamstring tightness includes inhibiting your stability and agility.

Because the hamstrings serve a double purpose of hip extension and knee flexion, they’re extra susceptible to injuries. Stretch, stretch, stretch and really make sure your muscles are ready to go before you get your hamstrings into deep squat positions.

Glutes

The gluteal muscles (your butt muscles) help keep the pace of your movement as you drop and come back up in your squats. This muscle group is made up of three muscles: the gluteus maximus, gluteus medius and gluteus minimus.

These are some of your strongest lower body muscles. It’s a good idea to engage your glutes at the top of a squat. Not only is this proper form, but it can be one of the best exercises for a round butt.

Calves

Your calves keep your body stable and connect you to your feet to stay grounded. The calf, made up of the soleus muscle and the gastrocnemius, helps you to plantarflex your foot (point your toes downward).

After you come to the bottom of your squat, your calves will engage to help you drive up through the heels and feet to bring yourself back up to a standing position.

Benefits of Smith Machine Hack Squat

Quad Growth

The Smith machine can help you train your quadriceps for hypertrophy. The forced path of motion on this machine lets you focus the effort on your quads.

Although we know that Smith machine hack squats are an effective training tool to achieve quad hypertrophy, the jury’s still out on whether they’re better than other similar exercises like the leg press.

To learn more, you can read: Leg Press vs. Smith Machine: Quadriceps Activation and Overall Perceived Effort Profiles.

Ability to Lift More Weight

Because of the added back support, you may be able to lift more in a hack squat vs a barbell back squat.

Trunk muscle activation at the same relative load can be higher in back squats. This requires your core muscles to do more work. On the other hand, the supported hack squat or Smith machine variation takes effort out of the core muscles.

A comparative study from the Journal of Strength and Conditioning Research suggests that hack squatting may lead you to heavier one-rep maxes.

Squat Stability

If you have poor balance, hack squats are a great way to improve your stability. The guided path of movement that your bar follows can be helpful if you are still working on your balance.

We may not see it, but barbell back squats require a lot of core stability. This comes from the abdominal muscles and you have to support your torso in midair if you don’t have a machine to work with.

Smith machines take the shakiness out of your squats if you’re having trouble balancing.

Some evidence shows that across the short- and long-term effects of resistance training with different stability requirements, athletes who train with a Smith machine may demonstrate improvements in trained exercises to be performed on a Smith machine rather than task-specific exercises.

Injury Rehabilitation

If you have suffered from any kind of injury and are coming back to squats, the Smith machine hack squat can be a good in-between option.

Since Smith machine hack squats do a lot of movement correction by design, you move within a smaller range of motion. If you have overextended your shoulders, hips, or any other joints, this can be a good way to keep your body upright and moving in a straight line so you don’t move beyond a comfortable range while you’re healing.

Beginner-Friendly

There are two schools of thought when it comes to using the Smith machine to assist exercises as a beginner.

On the one hand, machine-assisted hack squats cause you to miss out on a lot of core stability work that you would get when squatting with a barbell. On the other hand, some people consider the Smith machine to be “cheating” your core stability since you don’t build your muscular strength as gradually.

The bar path of a Smith machine is also perfectly straight so it’s not “natural” for most lifters.

Oftentimes, though, working with free weights can feel intimidating because you are unsupported. Machines have built-in safety features that give you more chances to bail out of a move.

How to Do a Smith Machine Hack Squat

• Set-Up: Adjust the bar to the height of your shoulders.  Get under the bar, grasping your barbell with an overhand grip.

• Body Postion: Holding the barbell up on your back, step forward to bring your body a comfortable distance away from the Smith machine.

• Squat: Drop your body down into a squat until your thighs are parallel to the floor. You kneed should come to a 90-degree bend. Keep your core braced and chest proud.

• Reverse: From the bottom of your squat, drive out of your heels to bring your body back up to the starting position.

• Reps: To train for hypertrophy, aim for 3 sets of 8-12 reps. For strength purposes, try to do 4-5 sets of 6 heavy reps.

The Takeaway

Smith machine hack squats are a great way to enhance your squat technique. If you’re looking to grow your quads, this is a great way to isolate these leg muscles and train for hypertrophy.

The Smith machine has some detractors. People who don’t prefer a Smith machine-assisted squat say that this method does not allow for a natural pattern of motion.

The straight direction of your barbell’s travel may overcorrect the natural shape of your squat. That being said, if you are a beginner who struggles with your posture and form or if you are returning from an existing injury, using the Smith machine can be a good way to improve your technique.

For those with hip mobility challenges as well, Smith machines don’t allow you to send your hips into as deep a hinge.

This may reduce stress on your hip joints for less hip pain when you squat.

All in all Smith hack squats are a great move to add to your arsenal but they’re not a perfect replacement for barbell back squats. Make sure to switch things up and try to incorporate different squat techniques unless you have a targeted fitness goal.

Using hack squats and squats, you should be able to see leg hypertrophy and strength gains in no time.

References:

Clark, D. R., Lambert, M. I., & Hunter, A. M. (2019). Trunk Muscle Activation in the Back and Hack Squat at the Same Relative Loads. Journal of strength and conditioning research, 33 Suppl 1, S60–S69. https://doi.org/10.1519/JSC.0000000000002144

Encarnación-Martínez, A., García-Gallart, A., Pérez-Soriano, P., Catalá-Vilaplana, I., Rizo-Albero, J., & Sanchis-Sanchis, R. (2023). Effect of Hamstring Tightness and Fatigue on Dynamic Stability and Agility in Physically Active Young Men. Sensors (Basel, Switzerland), 23(3), 1633. https://doi.org/10.3390/s23031633

Migliaccio, G. M., Dello Iacono, A., Ardigò, L. P., Samozino, P., Iuliano, E., Grgantov, Z., & Padulo, J. (2018). Leg Press vs. Smith Machine: Quadriceps Activation and Overall Perceived Effort Profiles. Frontiers in physiology, 9, 1481. https://doi.org/10.3389/fphys.2018.01481

Saeterbakken, A. H., Olsen, A., Behm, D. G., Bardstu, H. B., & Andersen, V. (2019). The short- and long-term effects of resistance training with different stability requirements. PloS one, 14(4), e0214302. https://doi.org/10.1371/journal.pone.0214302

Schick, E. E., Coburn, J. W., Brown, L. E., Judelson, D. A., Khamoui, A. V., Tran, T. T., & Uribe, B. P. (2010). A comparison of muscle activation between a Smith machine and free weight bench press. Journal of strength and conditioning research, 24(3), 779–784. https://doi.org/10.1519/JSC.0b013e3181cc2237