Single-Leg Box Squat
Exercise

Single-Leg Box Squat

Watch Video Instructions
QuadricepsGlutes and hamstrings
1 video
Workout Center

The single-leg box squat is a unilateral squat variation performed by lowering your body on one leg until your glutes lightly touch a box or bench, then driving back up to standing. It builds single-leg strength, hip and knee stability, and balance while giving you a consistent depth target, making it a practical stepping stone toward a full pistol squat. Because only one leg supports the load, it also exposes and helps correct strength imbalances between sides.

Muscles Targeted

  • Primary: Quadriceps, gluteus maximus
  • Secondary: Hamstrings, gluteus medius (hip stabilization)
  • Tertiary: Core and obliques (trunk stability), calves (ankle stabilization)

Starting Position

Stand facing away from a box or bench set at a height that brings your hips to roughly parallel or slightly above when seated, feet hip-width apart and the box just behind your heel on the working side. Shift your weight onto one leg and extend the other leg forward, holding your arms out in front of you for counterbalance. Keep your chest up and your standing knee tracking in line with your toes.

Execution Steps

  1. Shift your weight fully onto the standing leg while keeping the non-working leg extended slightly off the floor in front of you
  2. Push your hips back and bend the standing knee, lowering under control as if sitting toward the box
  3. Lower until your glutes lightly tap the box without fully sitting down or losing tension in the working leg
  4. Keep your torso upright and your knee tracking over your foot throughout the descent
  5. Drive through your heel to reverse the movement and return to standing, avoiding a bounce off the box
  6. Complete all reps on one side, then switch legs and repeat the same number of repetitions

Form Cues

  • Control the descent: Lower for a full 2-3 seconds rather than dropping onto the box
  • Tap, don't sit: Let the box lightly touch your glutes for a depth cue - don't rest your full weight on it
  • Track the knee: Keep your standing knee aligned over your foot rather than letting it cave inward
  • Keep your torso tall: Avoid excessive forward lean, which shifts load off the quads and glutes and onto the lower back
  • Use your arms for balance: Extend them forward or out to the sides as needed rather than fighting to stay upright with a rigid torso

Common Mistakes

  • Choosing a box that's too low: Excessive depth for your current strength causes loss of balance and knee cave; raise the box height until control improves.
  • Letting the knee collapse inward: Valgus collapse under load increases knee strain; consciously push the knee out in line with the toes.
  • Bouncing off the box: Using the box for a rebound instead of a controlled pause reduces muscle tension and increases joint stress.
  • Leaning too far forward: Excess forward lean overloads the lower back and reduces glute and quad engagement; keep the chest up throughout.
  • Rushing the tempo: Moving too quickly sacrifices control and balance, especially near the bottom of the movement; slow down both the descent and ascent.

Variations

  • Weighted single-leg box squat: Hold a dumbbell or kettlebell at the chest or by your side to add resistance once bodyweight becomes easy
  • Assisted single-leg box squat: Hold a rack, pole, or TRX strap lightly for extra balance support while building strength
  • Box pistol squat: Lower the box height progressively toward the floor as you build toward a full unassisted pistol squat
  • Rear-foot-improved variation: improve the non-working foot behind you on a bench for a split-squat-style hybrid with more hip drive

Tips for Progression

  • Lower the box gradually: Reduce box height in small increments as strength and balance improve
  • Add load: Once bodyweight reps are controlled and pain-free, add a light dumbbell or kettlebell
  • Reduce arm assistance: Progress from using a support for balance to performing the movement with arms free
  • Increase reps: Build toward 10-12 controlled reps per leg before increasing box depth or adding weight

Training Notes

Train single-leg box squats 1-2 times per week as part of a lower-body strength or balance-focused session, typically for 6-10 reps per leg across 2-4 sets. Rest 60-90 seconds between sets per leg. Because it's unilateral and balance-demanding, perform it earlier in a session while you're fresh, and use it to address side-to-side strength imbalances before progressing toward bilateral squat variations with heavier loads.

Exercise Details

Body Parts
Quadriceps, Glutes and hamstrings
Category
Workout Center

Frequently Asked Questions

How often should I do the Single-Leg Box Squat?

Because the Single-Leg Box Squat works quadriceps, glutes and hamstrings, two to three sessions a week is a sensible range for most people. It is a compound movement, so it pulls in several muscle groups at once and needs a full day of recovery before you hit the same pattern again. If you train it harder, do it less often.

Is the Single-Leg Box Squat suitable for beginners?

The Single-Leg Box Squat sits at an intermediate level for most lifters. Start light, nail the technique, and only add load once the pattern feels automatic. New to lifting? A coach can check your setup in a single session.

What should I do if the Single-Leg Box Squat causes pain?

Stop the set right away. A working burn in quadriceps is fine, but sharp or pinching pain is a signal, not a challenge. Reset your box setup, drop the weight, and if the pain comes back, talk to a physio or certified trainer before your next session.

How much weight should I use for the Single-Leg Box Squat?

Pick a load you can move with clean form for every planned rep, where only the last one or two feel genuinely hard. Since this is a pushing movement, keep the bar or handle path steady and avoid bouncing out of the bottom. When form holds across all sets, nudge the load up a little.

Can I modify the Single-Leg Box Squat?

Plenty of options exist. You can swap the box for something similar, shorten the range of motion while you learn the groove, or change your stance to shift the emphasis around quadriceps, glutes and hamstrings. Splitting a compound lift into its parts is a fair way to build the pattern. Adjust to fit your body, not the other way round.