Core Training Mistake #2:

Moving the lumbar spine when training the core.

Any respected fitness professional will tell you that movement in the lumbar spine is generally a
bad idea, for a few reasons.

The lumbar spine is designed to PREVENT motion of the body, not GENERATE motion. If it were not stiff and solid (similar to a supporting beam on your house) you would be constantly falling over all day, because you would have nothing to support the structure of your body to hold it upright.

Therefore, the very common, yet misguided practice of training the core to move is simply a waste of time. Nowhere in life do you crunch from the waist, sit up from the waist, or lean to the side from the waist. Training in that manner is ineffectual at best. It’s why we don’t perform crunches or sit ups at The Training Rim and it’s why this -

http://www.youtube.com/watch?v=lTaEhui8r2s

- is a stupid friggin’ exercise:

Secondly, and more importantly perhaps, is movement in the spine significantly increases the chance of injury to the low back. Because the abdomen is not designed to generate movement, the vertebrae of the lower back are specifically built to stop motion in the lower torso. Imposing movement there through inappropriate exercise choices increases the chance of vertebral movement and with it, the chances of slipped discs and compressed vertebrae and discs.

Bottom line: Stop with the crunches, sit ups, torso twists and side bends!