Illustration: Sam Woolley
Squats are one of the very best exercises for your legs, and nearly everybody who lifts heavy weights regularly does some form of squat. But perhaps you’ve heard that squats are bad for your knees, or that you need to do squats in a certain specific way to avoid injury. Let’s break down the specifics so you’ll know what advice to follow, and can rest assured you’re doing your squats the right way.
What muscles do squats work?
Technically, you already squat every day.
Every time you get up from a seated position, you’re effectively doing a squat. You probably feel your quads—the muscles in the fronts of your thighs—bearing the brunt of the work. Your glutes—aka your butt muscles—help to extend your hips while your quads are extending your knees. Besides a handful of other muscles in your legs and hips, the barbell back squat targets your core and back muscles, helping improve your posture.
The benefits of doing squats
While strong legs look nice in shorts and help us do everyday stuff with greater ease, you will appreciate them even more in your later years, as Greg Nuckols, writer and strength coach, points out. We sat down with him to talk about squats, and he notes:
Strong legs and hips, particularly, are crucially important for healthy aging. You can live independently longer, perform activities of daily living without as much strain, and muscle and strength are both strong predictors of longevity.
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We all know it becomes tougher to get up from a chair, toilet, or bed as we get older, but it’s never too late to start benefitting from building lower body strength or getting into strength training in general. A fairly recent study in the Journal of Strength & Conditioning found that heavy squats (under supervision) can help postmenopausal women suffering from osteopenia or osteoporosis improve bone mineral density in their spine and neck, in addition to boosting their strength.
Are squats safe for your knees?
If someone tells you to avoid squatting because “it’s bad for your knees,” this person probably doesn’t know—excuse the pun—squat about squats.
Don’t just take my word for it: A review article in Sports Medicine determined that the stresses of squatting to various depths, even the really low ones, don’t reach the point where they could cause harm to the ligaments in your knees (they’re sturdy like that, after all). In fact, the authors observed that the more you squat (with good form), the more your cartilage tissue can adapt and strengthen to handle the weight, just like your muscles do. The caveat here is that if you already have a history of knee issues, squats could aggravate your injury.
Otherwise, if you’ve got good technique and have healthy knees, squats can actually make your knees stronger and more injury-proof, as supported by the findings in a paper published in the Medicine and Science in Sports and Exercise.
So, it’s not the squats themselves that hurt your knees; it’s how you squat that’s probably hurting your knees.
How to do a proper squat
When you do a back squat, the weight should be centered over your foot, and stay there as your hips and knees bend. If you feel the pressure mostly in the front of your foot or mostly in your heels, you probably don’t have the bar on the most efficient up-and-down path.
You may have heard the advice that your knees shouldn’t go forward of your toes, but that’s no longer the consensus among trainers. Nuckols explains why:
Normally, people don’t really pay attention to how far forward their knees travel; they tend to balance the forces in the squat between their knees and hips pretty evenly. However, when you tell people to not allow their knees to track forward, or if you artificially restrict forward knee travel, a lot of the load is shifted to the back and hips, away from the quads, making it a less well-rounded movement for overall lower body development.
For the most part, your knees should track over your first or second toe. Having them track a shade further in or out isn’t the end of the world, but excessive knee valgus [caving in of the knees] should be avoided, especially if there’s pain that goes along with it.
Here’s an example of good squat form:
Basically, all great back squats share a few commonalities: they force the hips back, as if you’re sitting in a chair; they keep the chest up and facing forward to keep the spine from flexing (or else you’ll increase your risk of spinal disc injuries); and the knees don’t cave inward.
A good cue is to spread your knees out and wide during the lowering portion of the movement (although a small amount of inward movement coming up, as shown here, is generally okay as long as it doesn’t hurt, says Nuckols). Your feet, especially your heels, should stay planted on the ground, and your core should stay tight (here’s a video to teach you how to “brace” your core) throughout the lift.
How to get started if you’ve never squatted a barbell
The above video by YouTuber Omar Isuf is helpful for familiarizing yourself with squatting techniques, but you may not want to add weight until you can ace a bodyweight squat. “I believe that everyone should be able to comfortably hold a deep bodyweight squat position,” says Cody Lefever, a competitive powerlifter and the man behind a popular training structure called GZCL.
After all, bodyweight squats are a fantastic starting point to train your nervous system to groove to the squat pattern and get used to the movement. Keep in mind, though, that a nice-looking bodyweight squat doesn’t mean you’ll automatically be able to replicate perfect form when there’s a bunch of weight on your back. That’ll take practice, too.
Additionally, Lefever suggests:
Train that [squat] movement through goblet squats and work on both mobility and strength with single-leg work. Things like back-step lunges and Bulgarian split squats are great, as they address balance and coordination as well.
People often have a hard time staying balanced, but after working on goblet squats and the back-step lunge for a few weeks an improvement usually shows. If it is awkward reaching depth with just the bar, then focus on your warm-up routine.
On the other hand, if traditional barbell back squatting causes you pain or you’re not comfortable attempting them, there are multiple squat variations that can be just as effective for building legs, such as the front squat, goblet squats, and lunges. This paper in the Journal of Strength and Conditioning Research showed that front squats were just as effective for hitting the involved muscle groups as back squats—although keep in mind that front squats have their own learning curve.
Either way, you’ll need to take the time and effort to ease into these squat exercises.
Are deep squats safe?
The debates on the internet over how deep someone should squat are legion, but the gist is that deep squatting (or squatting “ass to grass”, as some lovingly call it) isn’t for everyone. We have a guide here to answering the question of how deep you should squat, depending on your goals in the gym.
Deep, ass-to-grass squatting does have a few more pronounced benefits. The deeper you squat, the more effectively you work the muscles involved and the greater the improvements in strength, as this study from the Journal of Strength and Conditioning Research explains. And as we already pointed out from the knee analysis study earlier, deeper squats don’t increase the risk of injury to your knees either.
But just because deeper squats are safe and demonstrably more effective at building leg strength, not everyone can (or should) squat ass-to-grass. Whether you do or not will largely depend on your history of injury, how your body is built, and your training goal, since different squats can work on different things. For example, partial squats (lowering yourself just a little) can be great for getting some serious power behind a jump, or for helping more advanced lifters work past difficult points in their squat. “The only people who need to squat [very] deep with weights are Olympic-level weightlifters,” Lefever says.
If you’re keen on squatting deeper, the good news is that you can learn to do so with practice. One way is by doing goblet squats, which give most people an easier time to “get to depth” since the weight is in the front of the body and changes the mechanics a bit. Once you’re comfortable with those, you can move on to the more challenging front squats. “By prioritizing range of motion and control of the lift more than the load on the bar until [they] master the movement, most people can squat deep if they’re willing to invest the time and effort,” Nuckols said.
How to make sure you’ll have a great squat workout
To be able to perform squats comfortably and effectively, you’ll first need decent flexibility in your hips, ankles, and upper back to help you get into the squat position with a barbell on your back (or in front of you if you’re doing front squats). Beyond that, here are other crucial tips to keep in mind:
- Squat first: You want to avoid being fatigued when you squat, or else you could increase your risk of injury and/or have an unproductive squat workout. If the day’s workout calls for heavy squats, you should probably do them first. The only lifters who routinely buck this trend are olympic-style weightlifters, who train the competition lifts when they’re fresh, and then squats afterward.
- Always be safe: If you’re squatting alone, make sure you can bail out of a bad lift when you need to. One way to help you do that is to set up the safety bars (adjustable bars that run perpendicular to the barbell on either side of you) to an appropriate height, just above the barbell’s lowest point. So, if you’re having trouble driving back up, you can tilt your back slightly more upright and roll the barbell onto the safety bars instead. (Omar Isuf teaches you some “bail out” techniques in this video.)
- Strengthen your core: A strong core helps keep you stable and lift more weight safely. While some people argue that squats are an amazing core exercise, they’re not enough. Core exercises, like bird dogs, pallof presses, or “stir the pot”, should be done separately and in addition to squatting.
- Keep your torso tight: You need to make sure your torso, or core, is engaged before starting the squat. “While I’m squatting, I’m just thinking about bracing my abs and torso as hard as I can,” said Lefever. Here’s where a weightlifting belt can be helpful to create the abdominal pressure for your core to “brace against” in a heavy squat, to protect your spine, and to let you lift a bit more weight. There’s no evidence that wearing a belt makes your core weak either. For more information, Nuckols has a great article on the matter.
- Squeeze your shoulder blades together: Imagine squeezing your shoulder blades together to keep your upper back and traps stable. It helps to keep your elbows pointed down and towards your butt, not just pointing them backwards.
- Ditch the foam pad: Some people like to keep a foam pad cushioned between the bar and their traps, but the pad doesn’t let you properly rest the bar where it’s most comfortable for you.
- Focus on moving fast: Speed is integral. It keeps the movement fluid and gets you past trouble spots. If you find yourself struggling, keep your chest up and imagine relentlessly driving through your heels and pushing your traps into the bar.
- Adjust your grip: Most people would do well by having a wider grip to keep the bar steady, but feel free to play around a little bit. The more important thing is to have your wrists in a neutral position.
- Try weightlifting shoes: Weightlifting shoes provide feet and ankle stability during a squat, and they can help you squat a little deeper because of the raised heel, too. Shoes are a pricey investment, though, so make sure you really, really like squatting.
- There’s no one way to back squat: We’ll all squat a bit differently due to the way each of our bodies is built. These differences in anatomy will mean that a comfortable and safe squat may look differently for you than it does for me, including how deep you squat, how wide your stance is, where your hands are, or how far forward you lean.
As with deadlifts, squats are highly technical and highly individual. Of course, the most important thing to remember is to avoid going heavier than you can safely handle. And don’t fret if you can’t squat to a certain depth—just keep yourself mobile and keep working on it. It took me a long time to get comfortable with the squat, and I’ve finally just broken into the 200s (90 kilos) myself after nearly a year!
This post was originally published in February 2016 and was updated on June 11, 2021 by Beth Skwarecki to update links and information and align with current Lifehacker style.