Exercise scientist Dr. Mike Israetel is breaking down two popular movements often included in leg day routines. Taking to his YouTube channel on September 19, 2024, Israetel compared the muscle-building benefits and drawbacks of leg presses and hack squats.
As an amateur bodybuilder and Brazilian Jiu-Jitsu practitioner, Dr. Israetel is constantly looking for new and creative ways to tax the body with exercise. He’s a credentialed physiologist with years of experience not just in academia but also through hands-on research courtesy of workout demonstrations on his YouTube channel Renaissance Periodization, which houses over 2.5 million subscribers.
“Let’s talk about leg presses versus hack squats for muscle growth. What is the difference and which one should you choose for your own programming.”
Leg Press vs. Hack Squat: Key Differences and the Best Choice for Muscle Growth
Below, you can find a science-based guide on whether to include leg presses or hack squats into your leg day routine.
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Leg Press Benefits
- Targets the quads very well
- Target the glutes and adductors quite a bit as well
- Leave lower back mostly alone
- Have low systemic and axial fatigue contributions
After exploring the benefits of the leg press, Dr. Israetel examines some of its costs and drawbacks.
“One is the leg press machine you’re using can be poorly designed in a few ways. The first way is it has a bad seat angle or it has stoppers to the plate mechanism such that you can’t get a really deep range of motion.
If the seat angle is really bad in respect to the plate or you have stoppers, you might not even be able to go down for a big deep quad stretch and thus you’re eliminating literally the most scientifically validated part of the range of motion.”
A poorly angled footplate can also serve as a barrier to making gains as it can limit the range of motion.
“It may have a poorly angled footplate, especially if the footplate doesn’t angle towards your heels but angles instead away from your heels. It can really limit the range of motion you get and thus results.
If you want a big range of motion out of it you might have to do it off your tippy toes which limits how much force you can produce and marginally increases the chance of injury unless you make the weight a lot lighter.”
Hack Squat Benefits
- Targets the quads very well
- Targets the glutes a bit and adductors decently as well
- Leaves the lower back mostly alone
- Have low systemic and axial fatigue contributions, but, more axial fatigue than leg presses
- Can’t slip out of a hack squat, so definitely superior to leg pressing in that regard
Dr. Israetel also laid out some of the disadvantages of hack squats.
“Hack squatting has some downsides as well. It can be poorly designed to limit bottom-end range of motion. A lot of times hack squats, the belt will run out or there’s stoppers you can’t move, you got to try to weld them out, which I’ve tried to do with machines before with limited success but it ends up being like you literally can’t get a full stretch because the machine just stops,” he shared.
Similar to leg press machines, the footplate can be at a less-than-ideal angle, which could sabotage your gains.
“Very concerningly for many hack squats, the footplate can be at the wrong angle, again, requiring you to take a very deep heel position and thus your calf tendons and ankle joints stop you from being fully mobile on the exercise.”
Which One Is Best For Your Workout Routine?
- Use whichever one that gives you the highest SFR (stimulus-to-fatigue ratio) and isn’t stale
- Use whenever you want quad stimulus with some adductor and glute involvement
- Use whenever you want a big quad stimulus with lower systemic and axial fatigue
- Use whenever your other main growth movement for quads that week is the barbell squat
For beginners, Israetel says to stick with barbell squats, lunges, and other free weight movements whereas for intermediate lifters, he advises them to use both the hack squat and leg press based on what nets the highest stimulus-to-fatigue ratio.
For advanced lifters, Israetel believes they should focus on hack squats and leg presses based on what produces the best SFR. He also advocates for specific setups and rep ranges that are ideal for the individual lifter. He also recommends experimenting with myo-reps and other intensifying modalities.
Whether he is analyzing the workouts of celebrities like Hugh Jackman or critiquing the training of Ronnie Coleman, Dr. Israetel always backs up his content with science-based tips. Based on your experience level, feel free to incorporate his guidance into your next leg day workout.
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