The Smith machine squat is one of the most controversial strength-training exercises out there. The Smith machine, a metal rack with a bar that travels along a fixed path, is used by beginner lifters and bodybuilders alike for squats and bench press variations.

It's also scoffed at by many and called "useless," "not functional," and just plain bad. But while the machine does have its drawbacks, it's unfair to say it's always a bad idea.

In fact, there are ways and reasons to do Smith machine squats safely and effectively. Let's outline the benefits and drawbacks and how you can do a Smith machine squat to learn perfect squat form and build stronger quads.

Why Is It Called a Smith Machine?

The Smith machine was developed in the 1950s by Rudy Smith, then the manager of a Los Angeles gym called Vic Tanny’s, according to his 2010 obituary. The idea for the machine was actually created by Smith’s friend, legendary TV host Jack LaLanne, before being built by Smith.

How Much Does the Bar Weigh on a Smith Machine?

There’s no single answer. Different machines have different bar weights. But they’re all usually lighter than the standard free weight barbell, which is 45 pounds. Chances are, the Smith machine squat weight you can lift will be more than what you can lift with free weights, since the machine takes much of the balance work out of the equation.

Part of what people consider a Smith machine ​con​ is also a check in the ​pros​ column. The machine does most of the stabilization work for you, which can make the move a little easier to execute. You don't need as much core strength to do the lift properly with good form.

If you're not comfortable squatting with a free-weight barbell on your back or you don't have access to a squat rack, the Smith machine can be a safer way to squat without worrying about tipping over. This allows you to practice your squat form, get comfortable and graduate to free-weight squats eventually (if you want to).

Because free-weight squats require more stabilizing muscles to balance, they're almost universally preferred for sports and powerlifting training: Moving a free weight like a barbell is closer to what you'll do in sport.

But if your goal is to build bigger quads, as bodybuilders do, losing the balance requirement means you can concentrate on driving the bar up and squeezing the muscles you want to build.

According to the July 2020 study mentioned above, weight machines — including the Smith machine — allow people to build the same amount of muscle and strength as lifting free weights.

Because you don't have to balance the bar, the Smith machine lets you do squats not just with your feet directly under the bar but a little further forward, leaning slightly back. Some bodybuilders claim this helps them target their quads more.

But for Brandon Lirio, CPT, director of BattleGround Fitness and professional bodybuilder, it's an alternative way to train what many lifters are getting from lifted-heel or slant board squats: deeper squats without leaning forward too much.

"Step out by about a foot, and then lean back on the Smith machine bar," he says. "Then perform the squat." You'll be able to squat deeper, and because you're leaning back, you'll be forced to keep the weight in your heels, not forward onto your toes. That's helpful, as lifting your heels without proper squat form can lead to lower back pain or injury.

Why Shouldn’t You Use a Smith Machine?

Because every body is different. Some in the anti-Smith camp argue that the Smith machine's fixed path was designed for one specific body — and that if your body isn't that size, your legs won't move along the "correct" path.

Basically, in this argument, the Smith machine provides train tracks, and your train's wheels might not fit on those tracks. People believe that this can cause you to contort your legs to fit the track — a forced form that can lead to injury.

Research, like this March 2011 study in the ​Journal of Sports Science​, backs this up: Because of the Smith machine's support, squatters can put their knees and backs into extreme positions that they wouldn't be able to with a free-weight barbell.

Some research has also found that the Smith machine doesn’t tax your muscles quite as hard, and because you don’t have to balance, doesn’t train the smaller, stabilizing muscles you’d be working with a free-weight squat.

This lack of stabilization arguably makes the Smith squat "less functional," meaning it doesn't translate to real-world use of strength as much. In the real world, you'd use the big muscles ​and​ those stabilizing muscles to squat down and stand up.

As with all squats, you want an upright torso when doing a Smith machine squat. Just because the bar is fixed doesn't mean you can't round forward. To avoid that, think about having a "proud chest" at the start and stay proud through each rep.

One way to help: As you set up with your hands on the bar, narrow your grip by about an inch on each side if you can. This will help you naturally keep your chest up.

If the bar is too high on your neck before you twist it to unrack, the barbell and all of the weight will be resting on the vertebra in your neck. This can cause bruising, pain and injury. Make sure the bar is set up on your shrugging muscles, or trapezius, before you unrack it.

You can go deeper if you'd like — and train to do so by moving your feet forward slightly before starting. But to get the benefits of a squat for your glutes, make sure you descend until your thighs are at least parallel to the floor.

When you descend in any squat, the angle of your shins and your back should be just about parallel, meaning they're at approximately the same angle. This will ensure you're keeping your torso up and putting the weight in your heels. If you can peek in a mirror or take a video while you squat, make sure these angles are the same at the bottom of the move.

If you're not used to squatting in a Smith machine, set the safety stops. These stoppers along the weight track can be set so that if you fall or lose control, the bar won't come crashing down on top of you. This is an added security in addition to the track to keep you safe and comfortable while squatting.

Which Way Should You Face When Squatting on a Smith Machine?

Most lifters face out of the Smith machine while squatting, so the bulk of the machine is behind them. If the machine you're working on travels straight up and down, you could face either way — if you want to face a mirror to check your form, for instance.Some Smith machines are slanted to supposedly make it easier to achieve a natural range of motion. If you're using an angled or slanted Smith machine to squat, you'll want to face away from the machine to save your knees.

This version will let you squat slightly deeper. If you want to squat deeper on regular, free-weight squats, this can be a good teaching tool.

Bodybuilders swear by this version, saying it works their quads harder than back squats or Smith machine back squats.

Split squats let you train one leg at a time. Using a Smith machine for this move lets you concentrate on the working leg without worrying about balance, so you can use slightly more weight than you would for a dumbbell split squat.

The goblet squat is a good Smith machine squat alternative if your gym doesn’t have a barbell, but you want to start doing free-weight squats. The goblet squat can help you keep your balance: The dumbbell held in front provides a good counterweight so you can lean back into your heels.