Swap sit-ups for ab crunches ... of crunches you do. This is all about mind-muscle connection; minimal movement with big results. So concentrate on the muscles you feel are being worked ...

Considered the opposite of the standard crunch, a reverse crunch is an effective exercise that targets the lower abdominal muscles and obliques ... If you’re not used to working your core ...

Build endurance and core muscle simultaneously with this three-move ab workout — without crunches ... but make sure you’re working toward the heavier weight range to keep your body under ...