Core training: the term is as ubiquitous in the fitness world as functional training, hot yoga, or HIIT. But are we really clear about what we mean when we discuss working the core? Is it simply abdominal work? Among many fitness professionals and exercisers the two terms are often used synonymously, but is this correct? In this post, I will attempt to explain what core muscles really are and just why they are so important. And it goes way beyond the pursuit of the perfect "six pack."
According to the authors of Fit & Well: Core Concepts and Labs in Physical Fitness and Wellness*, core-muscle fitness is defined as follows:
"The core muscles are the trunk muscles extending from the hips to the upper back...There are 29 of these muscles, attached to the ribs, hips, spinal column, and other bones in the trunk of the body. The core muscles stabilize the spine and help transfer force between the upper body and lower body. They stabilize the midsection when you sit, stand, reach, walk, jump, twist, squat, throw, or bend. The muscles on the front, back, and sides of your trunk support your spine when you sit in a chair and fix your midsection as you use your legs to stand up...Strong core muscles make movements more forceful and help prevent back pain."
When a golfer begins a properly executed swing, he starts with ground-reaction forces and transfers energy through the legs and hips first, then through the torso and to the arms, and finally to the head of the club at the peak of the backswing, before transferring the built-up energy like a whip back down through the chain, resulting (hopefully) in solid contact with the ball, sending it propelling forward. In this and many more examples, this is about much more than just the rectus abominis (six-pack muscle). It involves a synchronized effort among contributors from different major muscle groups-- including the transverse abdominis (deep abdominal muscle), the muscles of the back (erector spinae and multifidis), and the gluteal muscles--to provide stability for the spine while transferring energy during sports movements and activities of daily living.
The best exercises one can do for the core are so-called "back sparing" exercises, ones that allow a person to stay in neutral spine while challenging the muscles of the abdomen, back, hips, and buttocks. Planking is the perfect example of such an exercise and there are many variations of the plank that one can do. The standard plank has one in a "push up" position from shoulders to ankles, but instead of resting on the heels of the hands, the weight is on the forearms. If you are a beginner, just doing a 30-second plank without sagging, or piking, or otherwise breaking form can be quite difficult. But as your low-back and abdominal muscles become stronger, you will extend your time to a minute and longer and will tremble and shake less and less.
A side plank (or side bridge) is a more difficult exercise, because it is concentrated on the internal and external obliques on one side of the body only. Consequently, the length of time a beginner can hold this position is often even less than 30 seconds. And actually, depending on your level of conditioning starting out, you may even want to do your side plank from the knees rather than the outside of your bottom foot. Regardless, your elbow should be aligned directly below the shoulder and the focus is on the obliques of the bottom (down elbow) side.
For a more challenging variation of the plank, try the "stir the pot" exercise. Begin by doing a standard plank, but with your elbows on a stability ball rather than the ground. Hold this for 30 seconds. Then stir clockwise slowly for 8 rotations but do not tilt your body to the left or right. Then stir counterclockwise for 8 rotations, while again not "tilting your table" to either side. Hold the plank for a little longer without stirring, aiming for a total of about one and a half minutes.
For back extensors (erector spinae) one can do a simple exercise called the Bird Dog. Start out by getting on your hands and knees. Then extend one arm and the leg on the opposite side, as if pointing to a downed bird, and pause at the top. Like stirring the pot, you don't want to tilt your table to either side. Keep things nice and even. Alternate sides for 8 to 12 reps.
Finally, for the glutes, try this exercise featured on mytpi.com. No special equipment needed, the glute bridge with leg extension is a great way to engage the powerful muscles that make myriad sports movements and activities of daily living possible. There's even a popular scientific theory positing that the gluteus maximus, the largest muscle in the human body, gave early hunters a distinct evolutionary advantage! Bottom line: this muscle is important; treat it as such in your training routine. (Note on the glute exercise: if the glute bridge with leg extension is too difficult, start out with a simple glute bridge and work up to the more advanced exercise.)
In addition to the above exercises, most any free-weight exercise done from a standing position challenges and strengthens the core muscles. When doing such an exercise--a front squat with dumbbells, for example--the core musculature provides stability and keeps the spine in proper alignment throughout each repetition. Also, TRX training is a great way to add a core component to each and every exercise.
My advice would be to start basic with one set of each exercise then work your way up to more advanced variations and multiple sets. And never resistance train the same body part two days in a row; your body needs proper time to rest and recover.
Hopefully this helps your understanding of what core training is and how it is best executed. For questions and comments, I can be reached at firstname.lastname@example.org.
* Fahey, Thomas D., Paul M. Insel, and Walton T. Roth. Fit & Well: Core Concepts and Labs in Physical Fitness and Wellness. New York: McGraw-Hill, 2011. Print.