To do crunches, lie on your back with your knees bent and feet flat on the floor. Cross your arms over your chest, and use your abdominal muscles to lift your shoulders off the floor toward your knees. Slowly lower back down to the starting position to complete one crunch.Continue Reading
Lie on your back on a cushioned area of the floor or on a mat. Bend your knees, and place your feet flat on the floor. Keep your feet flat as you complete each step of the crunch, or place your toes underneath a couch or another stable object to prevent your feet from lifting.
Cross your arms over your chest, and use your abdominal muscles to lift your head and shoulders off of the floor. Keep your lower back on the floor, and curl your shoulders toward your knees. Do not lift your entire back off the floor, and avoid lifting with swift, jerking motions, as this can cause back strain and discomfort.
To finish the crunch, slowly lower your head and shoulders back to the starting position, and keep your arms crossed over your chest.