Let me start by saying that this is one of the most misunderstood body parts in training out there. Many people have many, MANY misconceptions about the core; what it is, how to work it and WHY to work it in particular. I’m hoping to clear some of that up in this post. So, without further ado:
What is the “Core”?
Most people think the core means “abs” (abdominal muscles) and, further to this, they believe that that refers to the 6-packs muscles. First of all, that should be 6-pack muscle (singular). It is ONE muscle known as the rectus abdominus. The cuts are created by connective tissue. The number and shape of your visible abs depends only on the shape and position of that connective tissue. Secondly, your abs consists of four abdominal muscles; rectus, transverse (innermost) and obliques (inner and outer – on the side). Finally, your core consists of ALL stabilising muscles around the trunk area, front AND back. This means that lower back muscles (quadratus lumborum, for example) are part of your core also. There is some debate as to whether the hip flexors are core muscles, so we won’t include them for now. The purpose of the core isn’t to lift heavy loads, but rather to stabilise the body through almost ALL movement, from walking to lifting heavy loads.
How do we work the core?
Each muscle can be targeted (by itself or in groups) by the appropriate exercise. Rectus Abdominus, for e.g., can be worked with crunches, obliques with twisting movements (Russian Twists, for e.g.), all abs with planks. Contrary to popular belief, leaning side to side doesn’t effectively work obliques (they are secondary muscles in that movement), but it is still pretty good (provided you maintain proper posture) for your quadratus lumborum (they are the primary muscles for that movement). Lower back can be worked with good mornings (think of bowing like the do in Japan to say “Good Morning”). By the way, situps are not only bad for your back (even worse than crunches), but they also target hip flexors more than abs (as would any exercise involving a hip hinge as the “positive” movement). All of these are great exercises to specifically target the muscles, but, overall, research has shown greater core activation during the two biggest lifts in weightlifting of any kind — the squat and the deadlift. Many powerlifters and bodybuilders who use these exercises as staples don’t do any specific core work. Once performed properly, most, if not all, of your core muscles are INTENSELY activated during these two lifts.
Why do we work the core?
Here’s another misconception. Many people work the core to get “abs” (the flat stomach or the 6-pack). This is one of the most INEFFICIENT ways to achieve that goal. The only way to do it is to lose fat and working core muscles doesn’t burn enough calories to make a major difference in fat loss. We work core because we need a strong core to stabilise the rest of our movement. Imagine trying to lift a chair with a weak back (granted you lift with your legs and NOT your back, but your lower back comes into play for, you guessed it, stability). Walking, running, fighting, loving, lifting, driving… almost everything requires a strong core.
Based on these things, core work is necessary, not for aesthetics, but rather for everyday function. Training core for visible abs is like emptying a bucket with a spoon in the rain. You will be able to make some progress, but that progress is so minute that it is constantly being undone. The better bet is to get into a proper training programme that includes complete core work for function and which focuses, instead, on overall fitness and health.