Back Squat: How to Do It, Muscles Worked and Benefits

The back squat is the king of lower-body exercises. You rest a loaded barbell across your upper back, sit down between your hips until your thighs pass parallel, then stand back up. It loads your quads, glutes, hamstrings and core more heavily than almost any other movement, which is why it sits at the centre of nearly every serious strength programme. It is also more technical than a dumbbell squat, so it pays to learn the setup properly. Here is how to do a back squat, the muscles it works, and how to keep progressing safely.

How to do a back squat

You need a barbell and a squat rack or power cage set so the bar sits around collarbone height. Set the safety bars at roughly the depth of your bottom position.

1. Set the bar on your back. Step under the bar and rest it across the meaty part of your upper back (your traps), not on your neck. Grip the bar firmly a little wider than shoulder-width and pull your elbows down to create a solid shelf of muscle.
2. Un-rack it. Brace your core, stand the bar up out of the rack, and take one or two small steps back. Do not walk it out any further than you must.
3. Set your stance. Feet a little wider than shoulder-width, toes turned out slightly (around 10 to 30 degrees). Take a big breath into your belly and brace as if bracing for a punch.
4. Descend. Break at your hips and knees together, sitting down and slightly back. Push your knees out so they track over your toes, and keep your chest up and your whole foot planted.
5. Hit depth. Lower until the crease of your hip drops just below the top of your knee (parallel or a touch below). Done with control and sensible loads, a deep squat is safe for healthy knees (scoping review on the deep squat and the knee).
6. Stand up. Drive through your whole foot and push the floor away, keeping your chest up and hips and shoulders rising together. Squeeze your glutes at the top, breathe, and reset for the next rep.

Muscles worked

The back squat is a leg exercise with a big whole-body stabilising demand from carrying the load on your back.

• Quadriceps. The muscles on the front of your thighs straighten your knees out of the bottom and are the main movers, especially in a more upright high bar squat.
• Glutes. Your glute max drives your hips from the bottom back to standing, and squats are one of the most reliable ways to load it (systematic review of gluteus maximus activation). Squatting deeper recruits them more.
• Hamstrings and adductors. Your hamstrings assist hip extension while your inner thighs fire hard out of the deep position and a wider stance.
• Core and spinal erectors. Your abs and lower back brace to stop you folding forward under the bar, which is why heavy squats leave your midsection tired.
• Upper back and calves. Your upper back holds the bar in place and your calves stabilise the ankle throughout the lift.

To load these muscles you first need somewhere to rack the bar. Our guides to the best squat rack and best power cage cover safe options for a home gym, and a weightlifting belt can help you brace on your heaviest sets.

High bar versus low bar

Where the bar sits on your back changes the movement.

• High bar squat: the bar rests on top of your traps and you stay more upright. This keeps the emphasis on the quads and feels the most natural to most people. It is the best starting point for beginners and the standard for weightlifting.
• Low bar squat: the bar sits a couple of inches lower, across your rear shoulders, and you lean your torso forward more. This uses more hip and posterior chain, usually lets you lift more weight, and is favoured in powerlifting. It asks more of your shoulder mobility and lower back.

Neither is superior. Pick high bar to learn, and only experiment with low bar later if you want to chase maximal loads.

How deep should you go

Aim for at least parallel, where your hip crease drops just below the top of your knee. Squatting through a full range tends to produce greater strength and muscle gains than partial reps (review of deep squats and performance). Go as deep as you can while keeping your lower back from rounding under (the dreaded "buttwink"). If your back tucks at the bottom, your ankle or hip mobility is the limiter, so work on that and squat to the depth you can control in the meantime.

Benefits

• Serious full-body strength. Few exercises build the legs, hips and core together like the back squat, and that strength carries over to sport and daily life.
• Muscle and bone. Loading your legs heavily is one of the best ways to build lower-body muscle, and weight-bearing resistance work supports bone density.
• Better everyday movement. Standing up, carrying and climbing all rely on the exact pattern the squat trains.
• It anchors a programme. Because it is so demanding, a few hard sets of squats twice a week drive a lot of progress. The NHS recommends muscle-strengthening work for all major muscle groups on at least two days a week.

Common mistakes

Knees caving in. Letting your knees collapse inward wastes power and stresses the joint. Actively push your knees out in line with your toes as you descend and drive up.

Heels lifting or rocking forward. If your heels rise, that usually points to tight ankles. Work on ankle mobility, or squat in weightlifting shoes with a raised heel until your mobility improves.

Good morning squat. When your hips shoot up faster than your shoulders, the bar tips forward and your back takes over. Keep your chest up and drive your hips and shoulders up together.

Not hitting depth. Quarter squats let you pile on weight but short-change your glutes and hamstrings. Squat to at least parallel with a load you can control.

Losing the brace. If you let air out and relax your core at the bottom, your torso folds. Hold your breath and brace until you are standing tall again.

Skipping the safety bars. Squatting heavy without safeties set at the right height is the main way people get hurt. Always set them so a failed rep can be dumped onto them.

Sets and reps

A simple plan that works for most people:

• Strength: 3 to 5 sets of 3 to 6 reps with a challenging weight, 2 times a week. Rest 2 to 3 minutes between sets.
• Muscle: 3 to 4 sets of 8 to 12 reps, resting 90 to 120 seconds.
• Learning the move: 3 sets of 5 slow reps with just the bar or light weight, focusing only on depth, brace and knees out.

Add a small amount of weight once you can complete all your sets with clean form. When progress stalls, that is normal, so hold the weight for a session or two before pushing on. Pair squats with a hip hinge like the Romanian deadlift to keep your legs balanced front to back.

Recommended reads

1. The best squat rack in the UK
2. The best power cage in the UK
3. The best weightlifting shoes in the UK
4. How to do the front squat