Core strength is vital to everything we do, from sitting at the computer to carrying a load of heavy groceries, from playing competitive sports to playing with our kids. It helps improve our posture, protects the spine from injury, and gives us a strong center from which to move.
Our core muscles are the numerous stabilizing muscles that connect the bones of the rib cage, spine, and pelvis: primarily the abdominal and back muscles, and to some degree the iliopsoas and gluteals. These muscle groups work in opposing pairs. For example, the abdominals flex the spine, while the back muscles perform extension. Similarly, the various muscles of the iliopsoas and gluteal groups work in opposition to control the movement of the pelvis, which consequently affects the curvature of the spine.
While methods such as Pilates can be an excellent way of strengthening the core, exercising on an unstable surface has proven yet even more effective. The stability ball is arguably the most versatile of props, with exercises performed in multiple positions and working every part of the body. Its benefit lies in the fact that our core muscles are crucial to maintaining balance—and even more significantly, that these muscles will automatically be called into play anytime we are balancing on the ball.
This phenomenon is accomplished through what is often dubbed the “sixth sense.” Better known as the kinesthetic sense, or proprioception—our perception of the body’s position and movement—this sensory system is directly involved in our reflexes and muscle memory. Sensory organs of the visual and vestibular (inner ear) systems, as well as pressure and joint receptors throughout the entire body, provide information to the cerebellum (hind brain). The brain then instantly processes this information and sends a message to the muscles to respond—a sort of reflex response.
For example, merely sitting on the ball forces the core muscles to remain in a constant state of contraction—a state of equilibrium but also of constant flux. As we are balancing, our weight is continuously shifting. When there is a slight imbalance in our body, such as leaning to one side, the body will attempt to correct the imbalance by making subtle adjustments in the opposite direction. The weaker muscles are thereby strengthened, and our posture will gradually improve. An ideal state of balance is achieved when the body has found perfect alignment.
Clearly, the goal is to avoid falling off the ball; therefore, through frequent practice, our body instinctively learns which muscles to activate. By stabilizing ourselves on an unstable surface, new neural pathways are formed and ingrained into our muscle memory so deeply that the core muscles respond involuntarily to any shift in balance.
It is precisely because these reflex responses bypass the conscious brain that I believe the stability ball transcends many other methods of training. Whereas a technique like Pilates demands deep awareness and concentration in order to activate the proper core muscles, the primary focus on the ball is simply to perform the movement without falling off. It is unnecessary to visualize the specific muscles we intend to use, since the feedback is immediate and automatic: if we fail to work the right muscles, we will lose our balance. Bringing a sense of mindfulness to our workouts can certainly enhance the benefits; nevertheless, the advantage, ultimately, is that stability ball training requires relatively little mental effort, increasing our core strength quickly and effectively—and perhaps providing a bit of fun along the way as well.