Legs · Squat
Barbell Back Squat
The barbell back squat is a compound lower-body lift where you hold a barbell across your upper back and descend until your hip crease passes below your knee. It primarily trains the quadriceps and glutes, with the adductors, hamstrings and spinal erectors assisting. Most lifters train it for 3–5 sets of 5–10 reps.
Also known as: Back squat, Barbell squat, High bar squat, Low bar squat
- Muscle group
- Legs
- Movement pattern
- Squat
- Type
- Compound
- Equipment
- Barbell, Squat rack
- Difficulty
- Intermediate
What muscles does the barbell back squat work?
Primary movers
- Quadriceps
- Gluteus maximus
Assisting muscles
- Adductor magnus
- Hamstrings
- Spinal erectors
- Abdominals
The squat is driven by two joint actions happening at once: your knees extend and your hips extend. Knee extension under load is what makes the quadriceps the primary mover — they are the only muscle group that straightens the knee, and they work hardest in the bottom third of the rep where the knee is most bent.
Hip extension recruits the gluteus maximus and, more than most lifters realise, the adductor magnus. Both contribute most out of the hole and taper off as you approach lockout. This is why the sticking point on a heavy squat sits a few inches out of the bottom rather than at the top.
The hamstrings assist at the hip but are simultaneously being shortened at the hip and lengthened at the knee, so their length barely changes through the rep. They work hard isometrically and get very little stretch — which is why the squat is a poor choice as your primary hamstring builder. Pair it with a Romanian deadlift or leg curl.
Your spinal erectors and abdominals never move much either. They contract isometrically to stop your torso folding forward under the bar. On heavy sets this is often the limiting factor before your legs are.
Bar position shifts the emphasis. A high-bar squat, with the bar on the traps, keeps the torso more upright and biases the quads. A low-bar squat, with the bar sitting on the rear delts, produces more forward lean and a longer hip moment arm, shifting work toward the glutes and posterior chain. Neither is superior — low bar usually moves more weight, high bar usually builds more quad.
How to do the barbell back squat
Setup
- 1
Set the rack hooks at roughly mid-chest height. If you have to rise onto your toes to unrack, they are too high.
- 2
Set the safety bars just below your bottom position, so a failed rep can be dumped safely.
- 3
Grip the bar evenly, pull your elbows down and back, and squeeze your shoulder blades together to build a shelf of muscle for the bar to sit on.
- 4
Step under the bar and position it either on your traps (high bar) or across your rear delts (low bar). The bar should never rest on bare vertebrae.
- 5
Brace, stand up to unrack, and take two or three steps back — no more. Walking the bar out further wastes energy on heavy sets.
- 6
Set your stance around shoulder width with toes turned out 15–30 degrees. Slightly wider and more turned out generally suits taller lifters.
Execution
- 1
Take a big breath into your belly and brace your abs hard, as if bracing to take a punch. Hold that breath.
- 2
Begin by simultaneously breaking at the hips and knees. Think about sitting down between your feet, not just pushing your hips back.
- 3
Track your knees out over your toes as you descend. They should follow the line of your feet, not collapse inward.
- 4
Descend under control to at least parallel — hip crease level with or below the top of the knee — provided you can get there without your lower back rounding.
- 5
Drive up out of the bottom by pushing the floor away through your whole foot, keeping your chest and hips rising at the same rate.
- 6
Exhale as you pass the sticking point and finish standing tall with hips fully extended. Do not lean back or overextend at the top.
Common barbell back squat mistakes
Knees caving inward
The knees track inward on the way up, usually on the heaviest reps. This is almost always weak or under-recruited glutes rather than a technique flaw you can simply think your way out of.
The fix: Cue actively spreading the floor apart with your feet. Drop the weight to a load where it does not happen and build back up, and add direct glute work such as hip thrusts or abductions.
Hips rising faster than the chest
You come out of the hole hips-first and the squat turns into a good morning. The bar drifts forward of mid-foot and the load transfers off your quads onto your lower back.
The fix: This is usually either too much weight or weak quads relative to your hips. Add front squats or pause squats, and cue driving your upper back into the bar as you rise rather than pushing your hips up.
Forcing depth beyond your hip mobility
Chasing an arbitrary depth causes the pelvis to tuck under at the bottom — the so-called butt wink — which rounds the lumbar spine under load.
The fix: Squat to the depth you can reach with a neutral spine, and work on that depth over time. A slightly wider stance with more toe flare buys most lifters a couple of extra inches immediately.
Bouncing out of the bottom
Dropping fast and rebounding off the calves and hamstrings hides weakness at the hardest point of the rep and puts sudden load on the knees.
The fix: Control the descent over roughly two seconds and reverse without a bounce. Pause squats for a couple of blocks will expose and fix the weak position.
Heels lifting off the floor
The heels rise as you descend, throwing the bar forward. Usually limited ankle dorsiflexion, sometimes a stance that is too narrow.
The fix: Squat in flat, hard-soled shoes or weightlifting shoes with a raised heel. Widen the stance slightly and work on ankle mobility between sessions.
How many sets and reps?
| Goal | Sets | Reps | Load | Rest |
|---|---|---|---|---|
| Strength | 3–5 | 3–6 | 80–90% 1RM | 3–5 min |
| Hypertrophy | 3–4 | 6–12 | 65–80% 1RM | 2–3 min |
| Beginner / technique | 3 | 5–8 | Light, 3+ reps in reserve | 2 min |
Squatting heavy is expensive in recovery terms. Most lifters do well with one heavy squat session and one lighter, higher-rep session per week rather than three hard sessions. If your squat is stalling and everything else is progressing, look at your sleep and your total weekly leg volume before adding more squat sets.
Barbell Back Squat variations and alternatives
Goblet Squat
EasierHolding a dumbbell at the chest counterbalances you and forces an upright torso, which makes the movement pattern much easier to learn. The best starting point for a genuine beginner.
Bodyweight Squat
EasierNo load at all, so you can practise depth, knee tracking and bracing before adding a bar. The right starting point if the pattern itself is new.
Front Squat
HarderThe bar sits on the front of the shoulders, demanding a vertical torso. More quad-biased and far more demanding on your upper back, but you will move less weight.
Bulgarian Split Squat
AlternativeA unilateral option that exposes and fixes side-to-side imbalances and loads the glutes hard with far less spinal loading. Brutal, and a genuine squat substitute if your back is beaten up.
Leg Press
AlternativeTrains the quads and glutes with no balance or bracing demand. Useful for adding leg volume without adding fatigue to your lower back.
Frequently asked questions
How deep should I squat?
Aim for the hip crease to drop level with or below the top of the knee — commonly called parallel or below. Depth increases the range of motion the quads and glutes work through, which is generally better for muscle growth. But depth is only worth reaching if you can get there without your lower back rounding. Squat to the deepest position you can hold a neutral spine in, and extend it over time.
Are squats bad for your knees?
No. There is no good evidence that properly performed squats damage healthy knees, and considerable evidence that resistance training strengthens the tissues around the joint. Knee pain from squatting is usually caused by rapid load increases, poor knee tracking, or an abrupt bounce out of the bottom — not by the exercise itself.
High bar or low bar — which should I use?
If you are training for general strength and muscle, high bar is the simpler choice: it is easier on the shoulders and it biases the quads. If you compete in powerlifting, low bar usually lets you lift more weight because it shortens the range of motion and recruits more hip musculature. Many lifters run high bar in off-season blocks and low bar closer to competition.
How often should I squat?
Two sessions a week suits most intermediate lifters — one heavier and one lighter. Beginners often progress well squatting three times a week at moderate loads because technique practice matters more than fatigue management early on. Advanced lifters sometimes squat once a week and make up leg volume with variations.
Do I need a belt to squat?
Not for light or moderate work. A belt gives your abs something to brace against and typically lets most lifters handle a bit more weight, so it is worth using on heavy sets above roughly 80% of your max. Train your lighter sets without one so you are not dependent on it for basic bracing.
Hercules tracks every barbell back squat you log, shows you last session's numbers before you lift, and flags when your progress stalls.
Download on Google Play