There have been many conflicting articles and reports in media about what constitutes core strength & stability and whether or not it correlates to sports and fitness performance. On more than one occasion, it seems that the source material has either been misquoted or even misinterpreted. Let’s set the record straight.
We’ll start by defining the core. When people refer to the core, many people immediately associate it with endless crunches and sit-ups. What they imagine the core to be is the rectus abdominis, or the two long muscles extending from the bottom of your pelvis up to the xyphoid process and a couple ribs. In other words, they associate the core with the “abs.” Many people use these two terms interchangeably. The definition of the core, however, is everything from the hip flexors up to your traps, basically everything but the arms and legs. It’s all the muscles, both deep and superficial, surrounding your spine. Your abs are merely a part of the whole core. Keep these definitions in mind when reading on.
Many people quote a famous study by Martuscello et al that demonstrated better core activation during heavy squats and deadlifts than with targeted core exercises. A lot of these people, fitness and strength and conditioning professionals included, use this study as evidence that you will develop a stronger core without staple abdominal exercises. This line of reasoning is flawed for a few reasons. The study DID find greater activation in certain core muscles during heavy free weight exercises, BUT the muscles studied were deep spinal and pelvic stabilizers, NOT abdominals. When breaking it down, squats and deadlifts are all about hip and knee extension, so it makes perfect sense that small background stabilizing muscles would be highly active during heavy loaded squats and deadlifts. Your abdominals are designed to resist extension. So when performing an exercise designed to put you in extension, it would defy logic for your body to put itself in a situation where it worked against itself. in other words, Squats and deadlifts have not been shown to be effective exercises in training abdominal muscles. That’s not to say that the stabilizing muscles activated during these movements aren’t important or part of the core. This study has merely been misrepresented with the “interchangeable” terminology of “abdominals” and “core”. Only exercises designed to resist hip extension will help you develop your “six pack”.
Now that we’ve established the definitions, let’s move onto the importance of the core during performance and how prevalent it should be during training. There have been countless studies of the core and it’s relationship to exercises and training. We’ve already determined that deep core stabilizing muscles are an important part of spinal stability in big, multi-joint exercises like the squat. The literature shows that there is a moderate statistical correlation between core muscle activation and performance in big multi-joint exercises. However, there is a misinterpretation to be made here. Just because there is muscle activation key to the performance of the lift, does not mean that the function of these muscles will be improved by squatting or benching. Most deep stabilizing muscles are aerobic in nature. They are in it for the long haul and require longer, lower intensity exercises to improve their function. The majority of the prime movers in the squat are anaerobic and fatigue quickly. There just isn’t enough time during heavy squats to improve these small muscles. In a nutshell, you need these small players to play a role in the performance of the team but you have to find a way to improve them.
Only exercises that target core muscles will be the most efficient in developing them. If your goal is to improve your spinal and pelvic stability in the Back Squat, you need to select exercises that are designed to resist hip flexion and pelvic tilt. Light weight Glute-Hams, Hip Bridges, Back Extensions, and Good Mornings are a good place to start. If your goal is to target the abdominals, putting your body in a position to have to resist hip extension is going to be the best way to go about it. I won’t even go into the argument of the overstated dangers of spinal flexion so just to be on the safe side, Seated Russian Twists, Front Planks, or Stability Ball Knee Tucks are all going to greatly activate your abdominals.
So how predominant should these exercises be in your programming? Let’s start by asking what all of these exercises have in common? They all utilize slower-fatiguing musculature. The natural order of operations in programming a workout is to put the highest fatiguing exercises first. This is done in order to increase the proficiency of complicated movement patterns and reduce the inherent risk of injury when performing them. With that in mind, it would be smart to specifically target the core toward the end of the workout when all other muscles have been worked. The takeaway: while the importance of the core can’t be overstated when associating it with performance, it’s not necessary to base an entire program around it for most people. After concentrating on the rest of the workout, these muscles will have been pre-fatigued and ripe for development toward the end of the strength-training workout.
On a semi-related side note, it is also important to train the entire core, during a training cycle. That doesn’t mean that you have to do every targeted core exercise in the book each workout. It just means that over time, you want to achieve muscular balance around such an important part of your body.
In conclusion, YES the core is greatly important in postural control and stability of the body when performing complicated movements. However, that doesn’t mean it has to be the focal point of your strength training sessions.