Crunches

Description

Lie on your back with knees bent, feet flat on the floor. Curl your upper body forward, lifting your shoulders off the ground while contracting your abdominals. Lower back down under control. The crunch is the most basic abdominal exercise. Arnold emphasizes that the movement should be short and controlled—you don't need to come all the way up. The key is the contraction of the abs, not the range of motion.