RE: PLANKS
Hi, Patty!
I do think you could benefit greatly from adding plank work into your abdominal routine, which not only recruits the abdominals but also the lower back muscles. Plank exercises as part of abdominal / "core stabilization" routines can be found in Cathe's CTX Kickbox, CTX Power Circuit, Power Hour (I think), one or more of the Slow and Heavy Series workouts, and a very brief one on Circuit Max. ALSO, consider getting Cathe's new Ab Hits DVD or video (DVD for me - more routines, more combinations)!
Plank work, which focuses on using the core muscles to hold the trunk stable and straight as opposed to the spinal flexion action of supine crunches, is the other half of ab work because it recruits these muscles to perform the other major function of abs - stabilizing the spine - against the resistance of gravity. Further, plank work recruits the oft-neglected (and misunderstood) transverse abdominus, a cummerbund-like muscle that wraps horizontally around the trunk nearer the hips and acts to hold in the internal viscera and assist in forceful exhalation as in coughing or laughing. It is NOT "the lower abdominals"; in fact there is no such thing as a discreet set of "lower abdominals". The transverse abdominus also has NO motor function, so dynamic crunches like you've been performing will probably do them no good at all.
I only brought in plank work about 2-3 months ago, after years of supine crunching, and noticed a difference in about 3 sessions.
Hope this helps!
Annette Q. Aquajock