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  7. Stability Ball Single Leg Squat

Exercise guide

Stability Ball Single Leg Squat

  • Intermediate
  • Compound
  • Rep-based
  • Lower legs
  • Upper legs

A unilateral lower-body movement that builds functional strength and balance by using a stability ball for guided support against a wall. It primarily targets the quadriceps and glutes while the instability of the ball engages the core and stabilizing muscles of the ankle and hip.

Reviewed by the Crucible team · Updated June 2026

Watch the Stability Ball Single Leg Squat demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Calves
  • Glutes
  • Hamstrings
  • Quadriceps

Secondary

  • Abs
  • Hip flexors
  • Obliques

Equipment

  • Stability ball

Setup

  1. Place the stability ball between your lower back and a wall, leaning back slightly to secure it.
  2. Lift one leg off the floor, extending it slightly forward, and position your standing foot about 12 inches in front of your hips.
  3. Engage your core and keep your shoulders pulled back and down for a proud chest.

How to do it

  1. Inhale as you slowly lower your hips by bending the standing knee, allowing the ball to roll up your back as you descend.
  2. Continue the descent until your working thigh is nearly parallel to the floor, ensuring your knee stays behind your toes.
  3. Exhale and drive through the heel of the standing foot to return to the starting position.
  4. Maintain a controlled 3-0-1-0 tempo, focusing on a slow descent and a powerful ascent.

Form checklist

  • Keep the standing knee aligned with the middle of the foot; do not let it cave inward.
  • Maintain constant pressure against the ball to ensure it stays in place against the wall.
  • Keep the non-working foot elevated and the hips level throughout the entire set.
  • Ensure your weight remains centered over the heel and midfoot of the standing leg.

Pro tips

  • To increase glute activation, focus on driving your hips back into the ball as you descend rather than just dropping straight down.
  • Maintain a slow, controlled eccentric phase to maximize time under tension and improve joint stability.
  • Fix your gaze on a point straight ahead to help maintain balance and spinal alignment.

Make it harder

  • Hold a dumbbell or kettlebell in the goblet position to increase the load on the lower body.
  • Add a 2-second pause at the bottom of the movement to eliminate momentum and increase difficulty.

Frequently asked

What muscles does the stability ball single leg squat work?
The stability ball single leg squat primarily targets the calves, glutes, hamstrings, and quadriceps, and also works the abs, hip flexors, and obliques as secondary muscles.
What equipment do you need for the stability ball single leg squat?
The stability ball single leg squat uses stability ball.
Is the stability ball single leg squat good for beginners?
The stability ball single leg squat is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • 3 Point Standing HopsIntermediate · calves, glutes, hamstrings, and quadriceps
  • 4 Cone Single Foot Lateral HopsIntermediate · calves, glutes, hamstrings, and quadriceps
  • 4 Way Single Leg HopAdvanced · calves, glutes, hamstrings, and quadriceps
  • Alternate Knee Cross Over Sit Against WallIntermediate · calves, glutes, hamstrings, and quadriceps

Train this with a plan, not guesswork

Crucible builds the stability ball single leg squat into a precise program around your body, equipment, location, and time.

Download on the App Store