Exercise guide
Stability Ball Isometric Single Leg Squat
- Intermediate
- Compound
- Timed hold
- Lower legs
- Upper legs
- Waist
This exercise builds unilateral lower body strength and stability by using a wall-supported ball to challenge the core and leg muscles through a sustained hold. It is highly effective for improving balance and isolating the quadriceps and glutes while minimizing spinal load.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Place the stability ball between your lower back and a smooth wall, leaning back slightly to secure it.
- Stand on one leg, positioning the foot far enough forward so your knee stays behind your toes when squatting.
- Extend the non-working leg slightly in front of you or keep it bent and off the floor.
- Engage your core and keep your hands on your hips or extended forward for balance.
How to do it
- Inhale and slowly lower your hips by bending the working knee, allowing the ball to roll down the wall with your back.
- Stop once your thigh is parallel to the floor and hold this position statically for the prescribed duration.
- Maintain a steady, controlled breathing pattern while keeping the muscles of the standing leg under constant tension.
- Exhale and drive through the mid-foot of the standing leg to return to the starting position after the hold is complete.
Form checklist
- Keep your chest upright and avoid leaning too far forward.
- Ensure the knee of the standing leg tracks directly over the middle of the foot.
- Keep your hips level; do not let the non-working hip drop toward the floor.
- Maintain firm pressure against the ball to ensure it doesn't slip.
Pro tips
- Focus on 'gripping' the floor with your toes and heel to maximize glute and calf engagement.
- Imagine pushing the wall away with your back to increase the isometric tension in the quadriceps.
- Keep the non-working leg active and straight to help stabilize the pelvis.
Make it harder
- Hold a dumbbell in a goblet position or two dumbbells at your sides to increase the load.
- Incorporate small 1-inch pulses at the bottom of the hold to further fatigue the muscle fibers.
Frequently asked
- What muscles does the stability ball isometric single leg squat work?
- The stability ball isometric single leg squat primarily targets the calves, glutes, hamstrings, and quadriceps, and also works the serratus anterior as secondary muscles.
- What equipment do you need for the stability ball isometric single leg squat?
- The stability ball isometric single leg squat uses stability ball.
- Is the stability ball isometric single leg squat good for beginners?
- The stability ball isometric 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
- Band DeadliftBeginner · calves, glutes, hamstrings, quadriceps, and trapezius
- Barbell Hang Clean Below The KneesAdvanced · calves, glutes, hamstrings, quadriceps, and trapezius
- Barbell Mixed Grip DeadliftIntermediate · calves, glutes, hamstrings, quadriceps, and trapezius
- Barbell SnatchAdvanced · adductors, calves, deltoids, erector spinae, glutes, hamstrings, lats, and quadriceps