Single Leg Stability Ball Leg Curls (How To & Alternatives)

The Single-Leg Stability Ball Leg Curl is an advanced hamstring and glute exercise that challenges strength, balance, and core stability. By performing the movement one leg at a time on a stability ball, you increase muscle activation in the hamstrings and glutes while demanding strong hip and core control.

It’s an excellent exercise for building posterior chain strength and improving single-leg stability.

Primary Muscles Worked: Hamstrings, Glutes
Secondary Muscles Worked: Core, Calves, Lower Back (stabilization)
Equipment Needed: Stability Ball

How To Do Single Leg Stability Ball Leg Curls

Step-by-Step Instructions

Set-Up:
- Lie on your back with one heel placed on top of a stability ball and the other leg extended straight toward the ceiling.
- Keep your arms at your sides for support and brace your core.
- Engage your glutes and lift your hips off the ground until your body forms a straight line from shoulders to heel.
Execution:
- Pull the ball toward your glutes by bending your working knee, keeping your hips lifted throughout the movement.
- Squeeze your hamstring and glute at the top of the curl.
- Slowly extend your leg to roll the ball back to the starting position while maintaining control and hip height.
- Complete all reps on one leg before switching sides.
Tips for Proper Form:
- Keep your hips level, don’t let one side drop as you move.
- Focus on a slow, controlled motion (avoid jerking the ball).
- Keep your non-working leg stable and extended throughout the set.
- Drive through your heel, not your toes, to fully activate the hamstrings.

Key Benefits

Builds unilateral hamstring and glute strength.
Improves core and hip stability.
Reduces muscular imbalances between legs.
Excellent accessory movement for runners, athletes, and lifters.

Modifications and Variations

Easier Option:
- Perform the movement with both legs (Stability Ball Leg Curl) until single-leg control improves.
- Reduce hip height or range of motion to focus on stability.
Harder Option:
- Add a pause at the top of the curl for 1–2 seconds.
- Perform slow eccentrics (3–4 seconds extending the leg).
- Elevate arms off the floor for increased core challenge.

Common Mistakes

Dropping the Hips: Keep hips elevated and aligned throughout the entire movement.
Using Momentum: Move slowly, control the ball on both the pull and return.
Pushing with Toes: Drive through your heel for proper hamstring engagement.
Letting the Ball Drift: Keep the ball centered and aligned with your body.

Reps and Sets Recommendations

For Strength: 3–4 sets of 6–8 reps per leg.
For Hypertrophy: 3–4 sets of 8–10 controlled reps per leg.
For Stability/Accessory Work: 2–3 sets of 10–12 slow, precise reps per leg.

SL Stability Ball Leg Curl Variations

Stability Ball Leg Curls

If Single Leg Curls prove to be a little too challenging then you can try their ‘double leg’ variation.

The movement itself stays the same, the only difference is keeping both feet on the ball instead of just one. This version is still challenging, but dramatically easy than the single-leg version.

Use Stability Ball Leg Curls to build strength and confidence until you feel ready to take on the single-leg variation.

Single Leg Stability Ball Leg Curl Alternatives

Don’t have a stability ball? No worries. Give one of these alternatives a try:

Single Leg DB RDL

Single Leg DB RDL is one of my favorite single-leg hamstring movements.

Not only are they an effective hamstring strengthening exercise, but they also have the added benefit of being performed on the feet (or foot I should say). This provides the added benefit of balance and proprioception.

Single Leg Floor Sliders

Single Leg Floor Sliders are very similar to Stability Ball Leg Curls, the only difference being the piece of equipment used.

Furniture Sliders may be something you already have in your house and, if not, are really cheap to buy. You can get them at your nearest home improvement store or even on Amazon.

As for the exercise itself, place your heel on the slider and curl it toward you – exactly the way you would with the stability ball.

They are a very challenging exercise, but if you feel like they are even harder than they should be experiment with the surface your lying on. Some surfaces are more difficult than others for the sliders to slide on.