Stacking and packing the core; simplifying core strength.

Core strength is a concept that is broadly understood to be important, and yet broadly misunderstood. Do we need to do more sit-ups or crunches? Take up Pilates? Get an ab roller? Thankfully the answer is no, not necessarily. Truly one just needs to understand a few basic concepts, and with this most exercises can cultivate core strength.

Core strength all comes down to position and the necessary tone to maintain it. The ideal position for our core is that which gives us both the most leverage and and the greatest durability.

First off, it is good to start with an agreed upon idea as to what exactly ones core is. Human bodies can be described as a torso with five limbs, the fifth being our neck and head. Our core is that which our five limbs are attached to; namely our thorax and pelvis. For the sake of this discussion, we’re going to call our core the space between our diaphragm and pelvic floor. Truly what constitutes our core is much more than this, but visually and conceptually, it will work well to stay between these two places.


Now that we have our boundaries defined, we have to line them up: we need to learn to stack the core. This refers to attaining the middle position where our core is not only the strongest, but our five limbs are allowed the greatest mobility and leverage.

The human spine is built to move in a variety of directions, but it is built to be loaded, both for prolonged periods under light loads (sitting/standing) and most especially under heavy loads (lifting, explosive movements) held in its middle. It is in this middle that our spine not only has the greatest structural integrity, but the surrounding muscles steadying it have the greatest leverage. It is here in this middle we need to cultivate awareness, control and strength.

Where this middle exists, is actually somewhat controversial. Our culture understands that a hunched over hyperkyphosis is problematic, but often it will encourage the extreme reversal of this. This extreme opposite can be best understood as exaggerated military posture, and the horrible instructions to “suck in your gut and stick your chest out”.

Click HERE for a video demonstrating these two extremes, and the middle we will discuss.

Now it has been established that you need to load the lumbar spine in a slight lordosis (inward curve) to prevent injury (1), but an excessive lordosis carries serious issues of its own. Besides a common cause of local back pain, an excessive lordosis inhibits the gluteal musculature(2), limits hip mobility and contributes to hip impingement, knee pain, calf strains and foot problems. These are all bad things.

So we need just enough lordosis, but not to much. Perhaps we should just stand up really ramrod straight? Not necesarily. Looking above, your thoracic spine/ribcage will serve your arms best maintaining a slight kyphosis (outward curve).  Put simply, a sufficient thoracic kyphosis allows scapular purchase on your thorax, enabling your shoulders and neck to move fully. It also allows your diaphragm to function as a respiratory muscle, and your thorax to expand in all directions with inhalation. These are all good things.

So we need a little lordosis for our lumbar spine and a little kyphosis in our thoracic spine. Not to much, and not to little. One might think we have a goldilocks in our midst.

Thankfully there are simple landmarks that are available to guide this perfect position. Essentially, we need to achieve diaphragmatic and pelvic floor opposition.

How? Take the following exercise:

Sit on a firm chair upright, feet on the floor, knees even, hips and shoulders lined up.  Feel both your sit bones (ischial tuberosities) under you. Slouch and arch your back. Get it so you have both sit bones directly under you (often the left is harder to find). Once you have this, your pelvic floor is facing up.

Now, put your hands in your lower ribs. For the ladies, this is directly under the bra line. Sit up very straight and feel your ribs stick out. Now hide them. This is your diaphragm facing down. If you don’t hide your ribs, your over extending, if you go further, you are slouching.

For some of us this will feel very odd or very difficult, for others, one rib may be harder to hide than the other (typically left).

Click HERE to watch a video demonstrating  attaining diaphragmatic and pelvic floor opposition (stacking the core).

It is in this position that the muscles on all sides of our core posses their greatest levarage, and the spine itself deep within its greatest capacity to bear load.

Now this position is what is most durable in not only strenuous situations, but in prolonged ones as well. We must learn to sense this position in our daily lives, not just during regular exercise regimes.


Once we have stacked the core and achieved this middle/neutral position, we must then learn to pack the core. This refers to producing sufficient tone in the surrounding musculature to prevent this position from being lost.

There are dozens of muscles that cross your core, and all play a vital roll in creating stability in this area. The most efficient way to stabilize this area is via an abdominal brace. This involves a co-contraction of all the muscles that cross the spine, most notably the abdominals.

Now the image of a sucked/drawn in abdomen being ideal permeates our culture like a plague. Where the ideas that a sucked in gut is one of strength or value came from I do not know, but Hollywood in its golden years can likely be blamed. A drawn in belly is a weak abdomen. The necessary abdominal pressure to buttress the spine is poor with the abdominals pulled in. A braced, evenly toned abdomen is ideal and effective. Visualizing preparing for a punch to the gut is often helpful.

Click HERE for a video demonstrating sucking/drawing in vs bracing.

The intensity/tension of the brace is dictated by the task. The harder the task, the harder the required bracing to maintain diaphragmatic and pelvic floor opposition.

Now for this to be useful we must be able to move our limbs freely while holding this, and we must be able to breath. Note: There are times with very heavy lifting that a valsalva maneuver is necessary while abdominal bracing, but otherwise breath holding is not a useful long term strategy.

For some, they will not be able to even attain this position, for others, they will be able to attain it, but not breath while in it. For both, they will have to be taught how to relax into diaphragmatic and pelvic floor opposition. As I have noted previously, relaxing requires slow full exhales.

For those that can achieve this position and respire, progressive exercise of all varieties can be performed around this. Every worthwhile strenuous exercise is essentially a series of limb movements and challenges around a braced core. This is the strong, safe and durable central pivot position for all challenging and prolonged human movements.


Often I will meet folks that will have to work hard at establishing sufficient core strength to return themselves to the pain free lifestyles they desire.  At times longstanding faulty postural habits are a barrier to overcome, and they have to confront their ideal of what upright posture is. This can be challenging on many levels for them.

At times they will express, outwardly or not, great trouble letting go of their idealization of  a narrow, drawn in waist line. This is the scourge of “sucking in their gut and sticking their chest out”. Insecurity about ones body type/abdominal size, and idealizations of an hourglass figure that have been held onto for decades at times need to be discarded. Strong abdominals are flat barrels, strong torsos are thick.

Visualization of what you are trying to attain and work towards is often crucial. Having powerful and beautiful examples of what you are attempting to embody can be very helpful in re-centering one towards their intentions in their core strengthening/postural retraining.

A few public figures that I have found very helpful are Bruce Lee and Mikhail Barshnikov. A personal favorite of mine is the recent Pavel Tsatsouline. A quick viewing of the linked videos of these three physically brilliant individuals will give you an ideal to strive for.

Regardless of your activity preferences, the position and the approach remains the same. Learn to stack, learn to pack, and learn to practice this daily.


1. McGill, Stuart “Low BackDisorders: Evidenced-Based Prevention and Rehabilitation” 2nd edition 2007

2. Levangie & Norton “Joint Structure & Function: A Comprehensive Analysis” 4th edition 2005


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s