Core Strength. Core Conditioning. Core Exercise. Core Stability. We've been hearing these buzz words around the fitness industry for a while now, and yet misconceptions about the core, core muscles, core stability, how to strengthen the core, still abound. By now, most of know that having a "six pack" does not necessarily mean that you will have a strong core, so that rules out traditional sit ups... Or does it? Not at all! In the many writings on the core, either in books or articles, Pilates exercises are often mentioned as being superior in strengthening the core and increasing core stability, but we wanted to know WHY!!!!
Why does Pilates strengthen the core so effectively? Why will exercises targeting the abdominals in a Pilates class likely strengthen the core more than traditional crunches? The answer, and, ironically, the secret to flat abs: Pilates focuses on a key muscle of the core, the Tranversus Abdominus. The deepest muscles of the abdominal wall, the fibers run horizontally, creating a corset like effect. A strong Transversus Abdominis protects your lower back and internal organs, and, of course, strengthens your core. The Transversus Abdominis is engaged by pulling in the abdominal muscles in and toward the front wall of the spine (think of tightening a belt.) No change in spinal shape should result. Thus, a HUGE bonus of focusing on the Transversus Abdominis is that we can create the coveted flat tummy... the trademark sign of a true Pilates body!
But the Transversus Abdominis is not the only muscles of the core. Included in the group are the pelvic floor muscles, diaphragm, the multifidi, the internal and external obliques and the erector spinae. 
Think of your core as a cylinder, starting around the area of your sternum and ending at the bottom of your pelvis. The "sides" of the cylinder are created by your Tranverssus Abdominis and your multifidi at the deepest level, followed by your internal, then external obliques, and then the erector spinae. The "bottom" of the cylinder is comprised of the muscles of the pevlic floor, and the "top" of the cylinder is your diaphragm. With all these muscles activated, your core is good to go!
At our studio, Pilates on Fifth, we are often asked by clients and Pilates certification students alike about ways to measure core strength. Well, we've found a great test of core strength! In fact, Katherine searched books while Kimberly searched online, and we both came up with the same test! The book is "Framework," by Nicholas A. DiNubile, MD and William Patrick, and the same test is on about.com. The test was designed by Brian Mackenzie, a senior athletics coach (UKA 4) with UK Athletics, the United Kingdom's National Governing body for Track and Field Athletics. We have included the breakdown of the exercise below:
"Conducting the Test:
1. Position the watch or clock where you can easily see it. (We usually put it on the ground in front of us!)
2. Start in the Plank Exercise Position (elbows on the ground). Hold for 60 seconds.
3. Lift your right arm off the ground. Hold for 15 seconds.
4. Return your right arm to the ground and lift the left arm off the ground. Hold for 15 seconds.
5. Return your left arm to the gorund and lift the right leg off the ground. Hold for 15 seconds.
6. Return your right leg to the ground and lift the left leg off the ground. Hold for 15 seconds.
7. Lift your left leg and right arm off the ground. Hold for 15 seconds.
8. Return your left leg and right arm to the ground.
9. Lift your right leg and left arm off the ground. Hold for 15 seconds.
10. Return to the Plank Exercise Position (elbows on the ground.) Hold this position for 30 seconds."
(Quinn, 2008)Photo credits: Abdominals (
http://www.womenfitness.net/flat_abs.htm); Diaphragm (
www.yorkievitz.com/.../anatomy/thorax/index.htm); Pelvic Floor Muscles (
www.tracis.info/prepostnatalinfo.htm); Psoas Muscle (
http://www.lwcoaching.com/library/strengtheningpsoasmuscle.htm)