When someone says the word “core”, thoughts go right to six-pack abs or flat abdomen. When a balance exercise exposes difficulty, people tend to say “I don’t have a strong enough core. Well, it is a little more complicated than that, it is a yes, no, or “depends” type of scenario that determines the reason, but, a fact is that a stable core and a strong core are not the same. In order to talk about the difference between strength and stability, we need to know what is the definition of core.
The National Academy of Sports Medicine defines the core as the cervical and thoracic spine, including as well the lumbopelvic-hip complex. So, in other words, the core consists of everything within your center of gravity: abdominals, back, glutes, and so on. This, in fact, means, core exercises also work your hips, back, and all muscles in the midsection of the body. Core work is important, as it is where all movements begin. This proves that the core doesn’t just mean your “abs”.
Core stability means the muscles surrounding the spine contract and create force and core stiffness. We need to be stable and stiff before doing any kind of movement. This applies from having a stiff wrist to move a finger, all the way to having a stiff core in order to squat. Think of the spine as a cord that moves around. If weight was going to be put on the cord, it would move. To avoid this, there has to be something to keep the cord in place, and this is when core stability, and subsequently stiffness, come into place.
Core muscles need to be strong enough to “turn on” and contract, since when the core muscles contract, stiffness is created and the spine is stabilized. As having a strong core helps towards lifting, it is not the main contributor to the performance itself. Another common misconception is, if you have a strong back you should not develop back problems, right? Well, doing abdominal strength work such as Russian twists, or back strength work such as back extensions would indeed, increase strength, but they don’t translate into core stiffness.
That being said, the best way to increase core endurance and stiffness is to use isometric movements, meaning turning on the core muscles, however, with small or no movement. By using isometric core exercises, the spine will be safer at moments of pressure, making them ideal not only for back injury rehab and prevention but also in the training and enhancement of athletic performance. This is why someone can have a six-pack and yet, have poor core stability when it comes to deadlifting or performing a squat.
Between strength and stability, the main difference is that when someone is training core strength is training by producing force, whereas when training core stability, it is directed more towards stiffness and balance itself. An example of this would be to train sit-ups (force against gravity in order to stand up) and doing side planks (stability/stiffness). When working core strength, there is room for some flexion (rounding your back for crunches), as well as working certain areas of your core by themselves to strengthen them (back extensions).
Core stability is essentially the ability to maintain your posture and position, while core strength is producing force against resistance to gain mass and definition. Depending on the goals, both types of core training can be used. If the goal would be the oh so famous six-pack, strength work would be the way, if the scenario is lifting and performance, stability has the biggest role. Stability will have benefits for every type of individual as it means a stable spine. It can be lifting in the gym or lifting something at home or reaching down to pick something up. At the end of the day, the common goal should be to do any kind of activity in the safest way possible.