Abdominal muscles are rarely used to round up or down. We predominately use them to brace/girdle, hold in and create stiffness in order to transmit force. I know...huh? i.e. if you are pushing a bureau across the floor, your feet are on the floor and your hands are on the bureau. What's doing the pushing? Well obviously your legs and arms, but, if your abs couldn't brace and hold position, you'd fold up in the middle like a rag doll and nothing would get moved. Try it out. Just push against the wall and notice what happens with your abs. This is why doing some variation of planks or hovers has become common practice.

 

Now that's not to say crunches don't have their place, but when training for function, working your ability to brace is a better way to go. Ask one of our Personal Trainers for more information.