If you want to get the most out of your core strength while dancing, then you must understand how to train and to use the core muscles properly. Many dancers spend hours strengthening their core muscles, but then do not understand how to engage them during dance.
First, let’s define which muscles make up the core. The abdominal muscles, of course, include the rectus abdominis, the transverse abdominis, the internal obliques, and the external obliques. But there are also the mid to lower back muscles, which include the multifidus, the quadratus lumborum, and the erector spinae. The back muscles are just as important to strengthen and to use as the abdominal muscles. If one set of these muscles, either the back or the abdominal, is stronger than the other, then you will be very challenged to maintain good balance and posture during dance.
Now let’s discuss the three curves of the spine: the cervical (your neck), the thoracic (upper back), and the lumbar (lower back). These curves are there for a very important reason! They allow the body to maintain balance, to move in multiple directions, and to absorb shock without pain or injury. Keeping these curves present while you train and/or dance is vital to obtaining the most stable and strong dancing posture. A very common mistake that is made while strengthening the abdominals is to constantly flatten the lumbar curve, or lower back, into the ground. I encourage you to begin to try to maintain a neutral spine (middle picture) which includes a small lumbar curve while you are performing core strengthening exercises. If you find that your back is aching while doing the exercises in this manner, then a slight posterior pelvic tilt (bottom picture) may help. Whatever you do, stay away from the anterior pelvic tilt (top picture) while training and dancing! Your core is almost definitely not engaged in this position and the excessive arching of the back may lead to injury.
Overall, try to start thinking of your core in a more 3-dimensional way…that means, all the way around your body, and to stop thinking of it as just the abdominal muscles in the front of your body. When you engage the muscles in your core, try to visualize squeezing both the abdominal and the back muscles around your spine (like a wide belt or a corset), rather than squeezing only the abdominal muscles and flexing forward. If you learn how to engage these muscles altogether as you stand up to dance, your body will automatically lift up taller and stabilize stronger. If you’ve ever heard a dance teacher say, “Pull up!”, this is what he/she is referring to. A very important thing to note is that this type of core muscle engagement should not require holding your breath! You should be able to breathe freely while stabilizing the spine. Keep in mind that it may take some practice to truly understand the feeling of properly engaging your core muscles while training and dancing, but that you will gain amazing posture and balance, as well as protect yourself from injury, when you get it right!