Crunch - Legs On Exercise Ball
Muscles worked
Instructions
- 1Lie flat on your back with your feet resting on an exercise ball and your knees bent at a 90 degree angle.
- 2Place your feet three to four inches apart and point your toes inward so they touch.
- 3Place your hands lightly on either side of your head keeping your elbows in. Tip: Don't lock your fingers behind your head.
- 4Push the small of your back down in the floor in order to better isolate your abdominal muscles. This will be your starting position.
- 5Begin to roll your shoulders off the floor and continue to push down as hard as you can with your lower back. Your shoulders should come up off the floor only about four inches, and your lower back should remain on the floor. Breathe out as you execute this portion of the movement. Squeeze your abdominals hard at the top of the contraction and hold for a second. Tip: Focus on a slow, controlled movement. Refrain from using momentum at any time.
- 6Slowly go back down to the starting position as you inhale.
- 7Repeat for the recommended amount of repetitions.
table_chartRecommended sets and reps
These ranges vary depending on your training goal — adjust the load accordingly.
| Goal | Sets | Reps | Rest |
|---|---|---|---|
| boltStrength | 3–4 | 6–8 | 2–3 min |
| fitness_centerHypertrophy | 3–4 | 10–15 | 60 s |
| timerEndurance | 2–3 | 15–20 | 30–45 s |
About Crunch - Legs On Exercise Ball
This variation of the classic crunch places the feet on a swiss ball instead of the floor, which makes the hips less stable and forces the abs to work harder to keep the pelvis steady as the shoulders lift. The key cue is pressing the lower back into the floor before starting, which effectively isolates the rectus abdominis by limiting hip flexor involvement. As with any crunch, the range of motion stays deliberately short: the shoulders only lift a few centimeters, and quality of contraction matters far more than how high you rise. It's a great progression once the standard floor crunch starts feeling too easy.
check_circleBenefits
- check_circleAdds an instability element that increases ab engagement
- check_circleEffectively isolates the rectus abdominis
- check_circleA natural progression from the standard floor crunch
- check_circleLimits hip flexor involvement
lightbulbExecution tips
- lightbulbPress your lower back firmly into the floor before starting
- lightbulbKeep your toes touching to help stabilize the ball
- lightbulbOnly lift a few centimeters, focusing on the contraction
- lightbulbAvoid pulling on your head with your hands
warningCommon mistakes
- warningLetting the lower back arch and lift off the floor
- warningRising too high by recruiting the hip flexors
- warningMoving too fast and relying on momentum
- warningPulling on the neck with hands clasped behind the head
helpFrequently asked questions
Why put your feet on a ball instead of the floor?expand_more
The ball's instability forces the abs to work harder to stabilize the pelvis throughout the crunch.
Do I need a large ball for this exercise?expand_more
A standard swiss ball works fine; what matters is that your knees stay bent at 90 degrees once your feet rest on it.
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