How to do the Crunch - Legs On Exercise Ball

Steps

1. Lie flat on your back with your feet resting on an exercise ball and your knees bent at a 90 degree angle.
2. Place your feet three to four inches apart and point your toes inward so they touch.
3. Place your hands lightly on either side of your head keeping your elbows in. Tip: Don't lock your fingers behind your head.
4. Push the small of your back down in the floor in order to better isolate your abdominal muscles. This will be your starting position.
5. Begin 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.
6. Slowly go back down to the starting position as you inhale.
7. Repeat for the recommended amount of repetitions.

Tracking it in OneRep

Add the crunch - legs on exercise ball to a routine and your previous weight and reps sit beside every set, so the decision to add load is made by what is already on the screen rather than by memory. Exercise history and volume trends are one tap away, and logging works offline for the gyms where signal does not reach.

Because OneRep tracks food on the same timeline, a stall on this lift can be read against what you were actually eating that month — which is the difference between a programming problem and an eating one. More on that in tracking progressive overload without a spreadsheet.

Where the instructions come from

The steps above come from free-exercise-db, a public-domain exercise dataset. They are general guidance, not coaching for your body: if a movement hurts, stop and get someone qualified to look at it.