Barbell Single Leg Squat
- Target muscle
- —
- Equipment
- Barbell
- Body part
- Thighs
- Type
- Strength
The barbell single leg squat is a unilateral strength exercise for the thighs, training one leg at a time while you balance and squat down with a barbell across your upper back. It builds the quadriceps and glutes of the working leg, exposes and corrects side-to-side strength imbalances, and demands far more balance and control than a two-legged squat.
How to do the Barbell Single Leg Squat
- 1Set the barbell at upper-chest height in a squat rack with the safety arms positioned at roughly the bottom of your intended range.
- 2Step under the bar and rest it across your upper back (not your neck), gripping it slightly wider than shoulder-width to lock it in place.
- 3Unrack the bar, step back into clear space, and shift your weight onto one leg.
- 4Lift the non-working leg slightly off the floor in front of you, or place its toes on a low bench behind you to assist balance.
- 5Brace your core and squat down on the working leg with control, keeping your knee tracking over your toes and your chest tall.
- 6Descend as far as your balance and mobility allow — to a bench, a parallel thigh, or pistol depth — without letting the knee collapse inward.
- 7Drive through the heel and mid-foot of the working leg to stand back up to full extension.
- 8Complete all reps on one leg, then switch sides and repeat, and re-rack the bar safely when finished.
Form tips
- Master the movement with body weight or a single dumbbell before loading a barbell, since the bar removes your free arm for counterbalance.
- Keep your weight over your mid-foot and heel, not your toes, to stay balanced and protect the knee through the descent.
- Squat to a bench or box at first to set a consistent depth and give yourself a safe target to control the descent.
- Use a spotter or set the rack's safety arms at your bottom position so you can bail the bar if your balance fails mid-rep.
Common mistakes
- Loading the barbell heavy before balance is solid, which makes the lift unstable and raises the risk of falling under load.
- Letting the working knee cave inward, which stresses the knee joint and shifts tension off the target thigh muscles.
- Pitching the chest far forward to stay upright, which turns it into a good-morning and loads the lower back instead of the legs.
- Rushing the descent and bouncing out of the bottom, which sacrifices control and the balance the exercise is meant to build.
Frequently asked questions
What muscles does the barbell single leg squat work?
It trains the thighs of the working leg — chiefly the quadriceps and glutes — one side at a time, while also heavily taxing your balance and core stability.
Is the barbell single leg squat good for beginners?
It is an advanced movement because of the balance demand. Beginners should build single-leg strength with body-weight or dumbbell versions first, then add a light barbell once the pattern is stable.
How deep should I go?
Go as deep as you can control while keeping your knee tracking over your toes and your torso tall — to a bench, parallel, or full pistol depth. Squatting to a bench is a good way to fix a consistent, safe depth.
What's a good alternative to the barbell single leg squat?
A dumbbell or body-weight single leg squat lets you balance more easily and bail safely. Bulgarian split squats are a related single-leg option that's less balance-intensive.
How should I set up for safety with a barbell?
Work inside a squat rack with the safety arms set at your bottom position, or use a spotter, so you can drop the bar onto the pins if your balance gives out mid-rep.
