The Great Abdominals MYTHs...... First let’s understand the goals of Abdominal/Core training. Crunches are primarily performed with the intention of the traditional “6-pack” look. Core training (EX: leg lifts) is primarily performed for stabilization and sports specific reasons. An example of Abs training would be for the purpose of “6-pack” spot training; core training might be performed by boxers who require strong midsections but   not necessarily for looks. The Thoracic spine is generally capable of 30 degrees of spinal flexion. During the action of spinal flexion the Rectus abdominal contracts pulling the ribs toward the pelvis. Also taking place during the crunch is the action of the Posterior Pelvic Tilt. When the traditional Crunch is performed, the ribs move toward the pelvis and thus the “feeling” of    upper Abs is experienced. When reverse action crunches are performed, the pelvis is moved towards the ribs and the “feeling” of lower abs is experienced. In actuality you can’t separate the upper and lower sections  during any movement.·   While performing spinal flexion, not only does the thoracic spine flex but so does the lumbar spine. Every muscle of the core (Rectus abdominis, internal/external oblique and transverse) works in spinal flexion. Each side muscle will contract to assist in flexion and keep the spine from rotation. The Psoas Major (hip flexors) origins are attached from the spine and inserted into the lesser trochanter of the femur. ABDOMINALS ARE NOT ATTACHED TO YOUR LEGS so it is impossible for the abdominal muscles to pull the legs up. During the lowering phase of the leg lift, the abdominal muscles will isometrically (iso-same, metric-length) contract to protect the lumbar spine from increased Lordosis. Lordosis is when the spine increases the curvature and leads to bulging of the disc. During this action, the CNS (central nervous system) will send a signal to the Abs to counteract the action and protect the spine. If the goal required leg lifts to train for stabilization then the matter of keeping the lumbar spine from rising off the floor would be a priority. When the lumbar arch increases, the abdominal are no longer able to support and protect the spine from compression. If we wanted to concentrate on lower abdominal actions, we might try flexing the hips as to take the psoas major muscle out of the way and then performing a reverse crunch (posterior pelvic tilt). SLOW DOWN when doing crunches, why are ABS the only exercise that we try to do faster then the rest? Bottom line; ABS are created in the kitchen with proper nutrition. Many exercises are designed for variety but little thought was put into the relationship of spinal movements and excessive repetitions.