The phrase "ball crunches" refers to a type of exercise that involves crunching or contracting your abdominal muscles while using an exercise ball. Full definition
The combination of both Swiss ball crunch and plank circle can elevate the level of your abs exercise to a more effective and efficient manner. (get-a-wingman.com)
Electromyographic comparison of a stability ball crunch with a traditional crunch. (verywellfit.com)
Stability ball crunch for upper abs, Stability ball pikes for lower abs, seated medicine ball trunks rotation for oblique, and workouts with planks for entire abdominal muscles. (consumerhealthdigest.com)