Having washboard abs does NOT equal a strong core.
Having six-pack abs does not mean you have a strong core.
Most people assume that a person with muscular abdominals, a six-pack, or washboard abs is strong, healthy, and athletic. However, this is often not the case. While a small percentage of people with abs are indeed fit, strong, healthy, and athletic, having strong defined abs does not necessarily mean that your core is strong. A person with a strong core can come in all shapes and sizes, with different body fat percentages. It is difficult to look at someone's core and determine whether they have a strong core.
Let's consider some examples of sports. Bodybuilding is mainly for aesthetics and symmetry, and athleticism is not a requirement. Olympic lifting, on the other hand, requires strength, power, mobility, and skill. Most lifters do not have bulging muscles or six-pack abs, but they have plenty of muscle and a strong core. Their muscles are typically covered by a layer of fat. Therefore, it is challenging to assess a person's core strength based on their appearance.
Your core is like a soup can, a cylinder with a top (your diaphragm), a bottom (your pelvic floor), and walls made up of the muscles surrounding your midsection and spinal muscles.
Having a strong core means having the coordination and control to activate specific trunk muscles under load and creating stiffness around your lower spine. Since every sport has specific demands on an athlete's core, training must be sport-specific.
To build a strong core, start by learning how to breathe with your diaphragm. This mind-muscle connection can be challenging, but with a few coaching cues, you can learn how to activate it. The next step is to learn how to keep the intra-abdominal pressure under tension. This step takes time, and strengthening your core requires progressive overloading and a well-thought-out exercise program.