Exercise Ball Leg Curl
- Target muscle
- Hamstrings
- Synergist muscles
- Gastrocnemius, Sartorius, Soleus
- Equipment
- Stability ball
- Body part
- Thighs
- Type
- Strength
The exercise ball leg curl is a bodyweight hamstring exercise that primarily targets the hamstrings, with the calves (gastrocnemius and soleus) and the sartorius assisting. Lying on your back with your heels on a stability ball, you bridge your hips up and curl the ball toward your glutes, training hamstring strength and knee-flexion control without any added weight.
How to do the Exercise Ball Leg Curl
- 1Lie flat on your back on the floor with your arms at your sides, palms down for stability.
- 2Place both heels on top of a stability ball with your legs extended and close together.
- 3Brace your core and drive your heels into the ball to lift your hips off the floor into a straight-line bridge from shoulders to heels.
- 4Holding the bridge, bend your knees and curl the ball toward your glutes by pulling your heels in, keeping your hips high.
- 5Pause briefly when the ball is close to your glutes and your knees are fully bent.
- 6Slowly roll the ball back out by straightening your knees, keeping your hips lifted throughout.
- 7Complete your reps, then lower your hips back to the floor under control.
Form tips
- Keep your hips high and level the whole set so tension stays on the hamstrings instead of dropping to the floor between reps.
- Press your arms and shoulders into the floor to anchor your upper body and keep the ball tracking straight.
- Move slowly and deliberately — the unstable ball rewards control, and a slow tempo keeps the hamstrings working through the full range.
- Squeeze your glutes at the top of the bridge to support your lower back and stabilize the curl.
Common mistakes
- Letting your hips sag toward the floor during the curl, which takes load off the hamstrings and turns it into an easy roll.
- Rushing the reps, so momentum swings the ball instead of the hamstrings controlling each curl and return.
- Only half-bending the knees, which cuts the range of motion and leaves hamstring strength on the table.
- Pushing through your toes instead of your heels, which shifts the work away from the hamstrings and makes the ball harder to control.
Frequently asked questions
What muscles does the exercise ball leg curl work?
It primarily works the hamstrings, with the calves (gastrocnemius and soleus) and the sartorius assisting. The glutes and core also work to hold the hip bridge steady throughout the set.
Is the exercise ball leg curl good for beginners?
Yes. It uses only your bodyweight and a stability ball, so it's a joint-friendly way to build hamstring strength. Beginners can keep their hips lower and curl through a shorter range until balance improves.
How do I make the exercise ball leg curl harder?
Perform it one leg at a time, slow the tempo, or pause longer at the top of each curl. Keeping your hips higher and your range fuller also increases the demand on the hamstrings.
How many sets and reps should I do?
For most lifters, 3 sets of 10–15 controlled reps works well. Because it's bodyweight, focus on full range and a steady tempo rather than chasing high rep counts.
