Need an ab workout, but you're tired of crunches? Dr. Brett McIff with the Utah Department of Health suggests trying a technique used by athletes around the world to stabilize the core and really work your hip flexors.
Lie on the floor, and place your fists under your hips to raise them off of the floor. Tighten your abdominal muscles as if you are starting a crunch or sit-up. Raise your feet off of the floor by about 2-4”. From this starting position, alternately raise and lower your legs up to about a 45 degree angle, one leg at a time. Repeat this for 10-20 repetitions, 1-3 sets.