FITBODY Exercise Library · Legs
Barbell Back Squat
The barbell back squat trains the quads, glutes, and hamstrings in one movement and loads the spine and hips hard enough to matter for bone density. Here is how to set up, how deep to go, and how much weight to start with.
How to Do a Barbell Back Squat
If you stall right at parallel and your heels want to lift off the floor, that is usually ankles, not strength. Put a 5 pound plate under each heel, or wear a shoe with a raised heel, and try the same weight again. Most women find another 2 inches of depth immediately, and depth is where the glutes get paid!
What Muscles Does the Barbell Back Squat Work?
The back squat is a knee and hip dominant compound lift, so the quadriceps and the gluteus maximus do most of the work. The quads extend the knee on the way up, the glutes extend the hip, and everything else in the chain is holding your torso steady so those two can produce force. That combination of large muscle groups under real load is why the squat earns a place in almost every program I write for body recomposition.
See the full muscle breakdown
- Quadriceps: Four muscles on the front of the thigh that straighten the knee as you stand up. They take on more of the load in a high bar squat, where the torso stays more upright.
- Gluteus maximus: The largest muscle in the body and the main hip extensor. It contributes most out of the bottom position and works harder as squat depth increases.
- Adductor magnus: Sits on the inner thigh and assists hip extension alongside the glutes. It is one of the reasons a slightly wider stance can feel stronger for many women.
- Hamstrings: Work across the back of the thigh to help extend the hip and to stabilize the knee. Their role in the squat is supportive rather than primary.
- Erector spinae: Run either side of the spine and contract without changing length to hold your back in a neutral position under the bar.
- Gluteus medius: Sits on the outside of the hip and stops the knees from collapsing inward as you drive up.
- Abdominals and obliques: Work with your breath to build pressure in the trunk so the load transfers from the bar into the floor instead of into your lower back.
- Calves: Stabilize the ankle and control how far the shin travels forward as you descend.
Back Squat vs Front Squat
The bar sits behind you in a back squat and in front of you in a front squat, and that one change moves the work around. Back squats let you handle more weight and put more of it through the glutes and hamstrings. Front squats keep the torso more upright, shift the emphasis toward the quads, and are less forgiving of a soft core.
Most women over 40 get more out of the back squat as their main lower body lift, with the front squat used as a secondary movement. I broke the two down side by side in my full front squat versus back squat comparison, including which one to choose for your goal.
Sets and Reps
How you load the back squat depends on what you are training it for. These are the ranges I use most often with clients.
| Goal | Sets | Reps |
|---|---|---|
| Learning the movement | 3 | 8 to 10 |
| Strength | 4 to 5 | 4 to 6 |
| Muscle and shape | 3 to 4 | 8 to 12 |
Rest 2 to 3 minutes between heavy sets and 60 to 90 seconds in the higher rep ranges. Squat early in the session while you are fresh, not after 20 minutes of accessory work. Add weight only once you can complete every rep at your current load with the same depth and the same bar speed, which is the same progressive overload logic I apply to every lift in a FITBODY program.
Variations and Modifications
High Bar and Low Bar
High bar places the barbell on the upper traps and keeps you more upright, which favors the quads. Low bar sits an inch or two down across the rear shoulders and tips you further forward, which brings in more glute and hamstring. Neither one is better. Pick the one your shoulders tolerate and stay with it long enough to get strong at it.
Goblet Squat
Holding a single dumbbell or kettlebell at your chest teaches the same pattern without loading your spine. This is where I start most women who are new to squatting, coming back from a break, or working around a shoulder that will not comfortably hold the bar.
Box Squat
Squatting to a box or bench gives you a consistent depth target and a moment to settle at the bottom. It is useful if your depth wanders from rep to rep, and it takes some of the fear out of the bottom position when you are learning to go lower.
Smith Machine Back Squat
The fixed bar path removes most of the balance demand, so you can push closer to failure without a spotter. The tradeoff is less trunk and stabilizer work, so it belongs alongside free weight squatting rather than in place of it.
If you are building a lower body day around this lift, the goblet squat and the Smith machine squat both pair well with it, either as a warm up pattern or as a second movement once the heavy work is done.
Common Mistakes to Avoid
- Knees caving inward as you drive up. This usually shows up on the last few reps of a heavy set and it puts the knee in a poor position under load. Widen your stance slightly, turn the toes out a little further, and think about pushing the floor apart with your feet as you stand.
- Depth shrinking as the weight climbs. Quarter squats with a loaded bar feel productive and are not. If you cannot hit the same depth you hit last week, the weight is too heavy for today. Take a plate off and keep the range of motion.
- The chest dropping so it becomes a good morning. When the hips shoot up first and the bar travels forward, the lift turns into a hinge and your lower back absorbs the difference. Slow the descent down, brace before you move, and keep your ribs stacked over your hips.
- A long, unsteady walkout. Five shuffling steps out of the rack leaves your feet uneven and burns energy before the first rep. Two steps is enough for almost every rack setup.
- Letting the brace go at the top of every rep. Breathing out completely between reps means you start each one soft through the middle. Take your breath at the top, hold it through the rep, and reset only when you need to.
Barbell Back Squat FAQs
Is the barbell back squat safe for women over 40?
Yes, and for most women over 40 it is one of the more valuable lifts available. The LIFTMOR randomized controlled trial put 101 postmenopausal women with osteopenia or osteoporosis through 8 months of supervised barbell training built on the deadlift, back squat, and overhead press at 80 to 85 percent of their one rep maximum, and the group improved bone mineral density at the lumbar spine and femoral neck with only one adverse event across the whole trial. Loading the spine and hips is what tells bone to hold on to density, and light weights do not send that signal. The caveat is technique and supervision, not age, so learn the pattern with a light bar first and progress the weight gradually.
What is a good weight for a woman to back squat?
Start with the empty barbell, which is 45 pounds on a standard Olympic bar or 33 pounds on a women’s bar, and add weight in small increments once your form holds. If the empty bar is too much, a fixed lighter barbell or a broomstick is a completely reasonable place to begin. Over time, a common intermediate benchmark for women is squatting close to body weight for reps, with stronger lifters working up toward 1.5 times body weight. Those are reference points rather than deadlines, and a woman squatting 95 pounds with full depth and clean knee tracking is training more effectively than one grinding 155 pounds through half the range.
Do barbell back squats grow your glutes?
Yes. The gluteus maximus is the primary hip extensor and it does the most work coming out of the bottom of the squat, where the hip is at its most flexed and under the most tension. Depth matters here more than load does, because a squat that stops above parallel takes the glutes out of their strongest working range and hands the rep to the quads. Squatting to at least parallel, progressing the weight over time, and pairing squats with a dedicated hip extension movement will build glutes better than squatting heavy and shallow.
How deep should you back squat?
Aim for the crease of your hip to reach level with or slightly below the top of your kneecap, which is what most people mean by parallel or full depth. Research comparing squat depths has found that deeper squatting produces better transfer to strength and power than partial range squatting, so cutting depth to add weight is a poor trade. That said, depth is limited by ankle and hip mobility before it is limited by willpower, and forcing depth you do not have will show up as your lower back rounding at the bottom. Squat to the deepest position you can hold with a neutral spine, and work on ankle mobility separately.
What are the best shoes for barbell back squats?
The best squat shoe has a firm, flat, or slightly raised heel and a sole that does not compress under load. Dedicated weightlifting shoes with a half inch to one inch raised heel help most if your ankles limit your depth, since the heel lift buys you a few more degrees of shin angle. Flat soled shoes such as canvas sneakers work well for low bar squatting and for anyone who prefers to feel the floor. Running shoes are the one option to avoid, because the thick cushioned sole compresses unevenly and makes a heavy bar feel unstable.
Are back squats good for your back?
Squatting with good technique strengthens the erector spinae and the deeper trunk muscles that hold your spine in position, and a stronger trunk generally handles daily loading better. What squats do not do is treat or cure back pain, and a back squat performed with a rounding lower back under heavy load is a way to create a problem rather than solve one. If you have an existing back injury or ongoing pain, work with a physical therapist before loading a bar across your shoulders. For everyone else, keeping the weight moderate enough to hold a neutral spine is the whole answer.
References
- Watson, Steven L., et al. “High-Intensity Resistance and Impact Training Improves Bone Mineral Density and Physical Function in Postmenopausal Women With Osteopenia and Osteoporosis: The LIFTMOR Randomized Controlled Trial.” Journal of Bone and Mineral Research, vol. 33, no. 2, 2018, pp. 211 to 220, doi.org/10.1002/jbmr.3284. Eight months of twice-weekly barbell training including the back squat improved lumbar spine and femoral neck bone mineral density in postmenopausal women with low bone mass, with one adverse event reported. Training was fully supervised in small groups, which is not the same as training alone in a commercial gym.
- Myer, Gregory D., et al. “The Back Squat: A Proposed Assessment of Functional Deficits and Technical Factors That Limit Performance.” Strength and Conditioning Journal, vol. 36, no. 6, 2014, pp. 4 to 27, doi.org/10.1519/SSC.0000000000000103. A technique framework that maps common squat faults, including knee collapse and limited ankle range, back to the specific mobility restrictions causing them. It is a narrative review and screening proposal rather than an experimental study.
- Hartmann, Hagen, et al. “Influence of Squatting Depth on Jumping Performance.” Journal of Strength and Conditioning Research, vol. 26, no. 12, 2012, pp. 3243 to 3261, doi.org/10.1519/JSC.0b013e31824ede62. Deep squatting transferred better to jump performance and force production than quarter squatting, despite the heavier loads used in the partial range. Subjects were trained young athletes, so the findings speak to depth in general rather than to women over 40 specifically.
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I’m Julie Lohre, an IFBB Fitness Pro and certified personal trainer and nutrition specialist. For more than 20 years I have helped women over 40 get stronger, leaner, and more confident through personalized online coaching built around their real lives.