How to Do a Hipless Crunch
The stomach crunch and its numerous variations have long bee staples of fitness enthusiasts looking for core strengthening. The key to an effective crunch is using proper form so that the top-lying abdominal muscle -- the rectus abdominis -- is correctly worked. Often, the hip flexors, a muscle group located on the top of the thighs, take over during a crunch, which removes the emphasis from the abs. This can result in less muscle tone in the abdominals and overworked hip flexors, which then become tight. Neutralizing the hips by raising your legs in the air during the crunch helps to maximize the abdominal benefits.
Warm up your entire body with 10 minutes of jogging, jumping rope, cycling or other cardiovascular activity before performing any abdominal exercises. Follow the cardio with one 10-repetition set each of body-weight squats and lunges, which will help to activate your core and legs.
Lie on your back on an exercise mat. Pull your abdominal muscles in toward your spine to flatten your lower back. Press the shoulder blades down and away from your ears to straighten your upper back.
Raise your legs toward the ceiling, keeping them together, until your legs are perpendicular to the floor. Bend your knees to 90 degrees if tight hamstrings prevent you from holding your legs straight. Align your feet with your hips, allowing the feet to move in front of or behind your hips can activate the hip flexors.
Raise your arms toward the ceiling so that they are also perpendicular to the floor. Lift your head and shoulders off of the floor as you reach for your toes with your fingers.
Hold the contraction for one count at the top of the exercise and then release, lowering your head and shoulders back to starting position.