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The fitness industry revolves around Abs. Past, present, and future, Abdominals are often the centre of sports conditioning, rehabilitation, and of course, vanity. Gyms, fitness equipment suppliers, and now supplement companies have been quick to cash in on our obsession with abs. The latest term in this evolution is ‘the core.’


Core conditioning has become the number 1 catch phrase in the fitness industry in the 2000’s. Yet at times it seems the more we hear about our core, the more confusing it becomes. So I’ll try to and explain to you what it is, where it is, and why its so important… and no, there will be no selling of any ab burners, wonder kings, magic pills or anything else the industry seems to be selling whenever abs are mentioned.. I guarantee it!


What is the core?

The core can be divided into two Category’s:

Our Inner core

And Our Outer Core


The inner core is called the Transversus Abdominis (hence we like to use the term ‘inner core’!) and is a muscle which surrounds the lower spine, from your pelvic floor to your diaphragm and all around the sides to create a vacuum (the muscle can only be used for compression – not movement).

So imagine a balloon covering your spine that can be sucked in. As the balloon is sucked in (made smaller, yes making your waistline smaller too) the pressure increases. The more the pressure increases, the stronger and more resistant to stress it becomes. If the stress becomes   too great for the inner unit to handle, the overload of stress will be put on the spine (better that than popping the balloon, or in this case, spraining your muscles).

What makes this muscle so interesting, is that although it’s a muscle, it’s not involved in any movement, its job is simply to support the spine. Therefore, although it’s not directly responsible for any movement, it should be activated in ALL movements to support our spine!!!


Outer Core:

These are the muscles you can see, they are on top of your inner unit, so the layer of muscle just under the skin (and, um, fat?!).

These are the muscles which actually create movement (bending, twisting) through the spine. Unlike your inner unit, these muscles are not in a strong position to support the spine, so they must learn to work together – inner core supports the movement from your outer core…


Why has Core Training become so Popular?

Unfortunately, the inner unit does not function in most people, and this the number 1 cause for 90% of Australians suffering back pain at some point in their lives.


You know the importance of it, but training it is hard since it is not involved in movement, so rather than learning to ‘move’ a weight to strengthen it, you must learn to identify and activate it first (hence the popularity in Pilates classes where the focus is placed on identifying first, strengthening second). Prolonged sitting is the main culprit in today’s lifestyle because your inner core is not needed, so switches off. Your body honestly forgets how to use it and finds other muscles to compensate. It’s human nature, if your right handed you find doing things with your right hand easier, so you use it more. Your right hand gets stronger while your left hand gets weaker and over the years those differences compound – Try and brush your teeth or unlocking a door with your left hand, it’s hard! Your hand shakes because your muscles are ‘uncoordinated,’ which basically means your brain can’t find the right muscles to move at the correct speed and force. This is what happens to your inner core, it gets weaker through lack of use and since you do not ‘move’ them, it becomes hard for the brain to identify them before exercising / strengthening them!


“ So What do I do Now??”

Your first step is learning to identify the muscles (brain – muscle correlation).

Integrate the muscles so they learn how to work with our bigger muscles (outer unit, hips, legs etc) during movement. There’s no point only having muscles to work in the hover (plank) position because it’s when you’’re standing that injuries and strains occur.


Once you’ve identified the muscles, strength training can begin.

Train the muscles for Strength and Endurance first (Speed / Power comes later). As postural muscles they must be able to support our spine whenever you are NOT lying down! Hence, they need strength AND endurance.

Strengthen the muscles together so the muscles can be relied on to react quickly (sudden movements) and support heavy weights (lifting).


In summary, the inner core’s only responsibility is to protect the spine, as such is the harder muscle to identify and train! Training the outer core DOES NOT mean the inner core is working! It has been estimated that approximately 80% of adults cannot recruit their inner core (studies show that babies can, thus providing the evidence that we un-learn the muscle activation process through lack of use!).

This also means that the inner core is not working in these 90% of people’s Abdominal routines!

The outer core is closer to the skin and responsible for your six pack (rectus abdominis). Unless you lose the fat you will not see your abs, regardless of how much training they do. In my experience, a body fat percentage of about 12% is required for adominals to start showing.

More importantly, however, is to improve your core strength during movements, and you will greatly restrict your chances of back pain and increasing the transfer of strength and power from your legs to your torso.


Sam Struthers

Strength & Conditioning Coach
Personal Trainer

 North Sydney Gym; Bounce Fitness

37 Ridge St, North Sydney