What muscle is the core exactly?

Using your core is essential to any form of physical training. It is paramount for safety. Training your core to function, to tie your body together is a skill that you develop by using various drills. And then you subject it to higher levels of stress when you lift weights or get on the rings or doing whatever you do.

If you've been to a gym or dabbled in fitness, you've heard of this term. But what does it actually mean?

Is it a specific body part? Like the lats or biceps or whatever? Does it refer to the abs? Then why wouldn't we just say abs?!

The core is not one muscle or a muscle group. It is a catch-all term.

The core refers to whatever parts of the body that transfer power or work done. This varies between movements i.e. some movements have more moving parts, say the deadlift or running, while some movements have less moving parts, say the military press.

Daily Grind
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An example: The Olympic Snatch

The function of the core is to keep the bits that need to remain stable, stable. So that the bits that move can move better. Think how you are on a stable foundation (the floor) vs an unstable foundation (a BOSU ball). You want to have a stable foundation - internally. That's the function of the core. The bits (limbs) that move generate power (think legs in sprinting) and/or move the load (a kettlebell or Olympic snatch).

In the video above, Klokov is moving some ridiculous weight. Here is how the lift is done, without going into any technical detail.

  1. Legs drive into the floor.
  2. Hips take over.
  3. Together, #1 and #2 have generated the power to lift the weight. But that's not enough
  4. The core needs to transfer, with minimum transmission loss, this power/work done to the load. Else, the load won't be lifted.
  5. The load is held by the arms. The arms are connected to the shoulders.
  6. The legs and hips generate power. This power is transmitted upwards, through the mid-section (core), and to the shoulders, and voila - the barbell flies up.

In this example, the core is the trunk of the body, the pillar. The parts that are between the shoulder and the hip.

Power transmission lines

For your electronic devices to work, electricity is supplied to your house. The electricity is generated in some far-away place and then transmitted via power lines.

Due to various inefficiencies in the transmission, there is a significant difference between what is produced and what is eventually utilised. But that's the nature of the game.

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If we produced 100 units and our transmission efficiency is 50%, then we get only 50 units. There are two ways to increase the amount - produce more or improve transmission efficiency.

To get stronger or faster (and for better endurance or fat loss or almost any adaptation), you need to learn to improve both the production and the transmission efficiency.

In addition to transmission efficiency, a proper core function is mandatory to keep you safe.

A different example: The KB Press

What's the core here? The moving part is just the working arm. So, pretty much everything below it is the core.

Your glutes and your quadriceps, for example, are part of the core in a press. But in most movements, they are the prime movers.

The intent is not to confuse you but to drive the point home that the function is transfer of power and providing a stable foundation for the moving parts to do the moving and lifting.

Focus on the pillar

For healthy, safe lifting, you need to have a strong mid-section. Let's use the word pillar (Exos uses this and I think it is a good term that does the job) for the rest of this article.

While the core will change depending on the movement, to be a better lifter (or a gymnast or martial artist or anything in the realm of physical fitness), you need to have a strong and functional mid-section. Pillar!

This is not just your abs - the 6-pack. Instead, think of your pillar as a six-sided box.

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  1. The front of the box - that's your abs. And well, stuff underneath and near it. But pfft, irrelevant technicalities.
    Think of this as straps running from your sternum to the top of your pelvis. From somewhere just below your nipples to a bit below the belly button where some bony bits are (if you sit, you fold at your hip joint. Poke yourself at the part you fold, you'll see what I mean).
  2. The sides of the box - think of straps running from your armpit to your hips.
  3. The back of the box - think of straps running from your shoulder blades to your pelvis.
  4. The bottom of the box - this is your pelvic floor. When you sneeze, you squeeze this automagically. When you really need to pee but the loo is 200 metres away, you hold it in and walk real fast, right? That's the pelvic floor in action again.
  5. The top of the box - let's ignore this for now.

Shtraps, straps, shraps

You don't need to worry about what the actual muscles are called and all that. That's for you to geek out.

You simply need to know that you need to focus on (at least) the 4 sides of the box. The bottom and top are harder and will come by later.

Man wearing an Able Carry backpack taking a photo of Hong Kong at sunset
Photo by Able Carry / Unsplash

I like to think of straps running all around my body, from shoulder to hip. The straps run vertically and diagonally. When I set up for a lift, I tighten my straps. If I tighten too much in front, the front crunches/shrinks. If I tighten the straps at the back more than the front, I have a big arch on my chest (think Bench Press). Depending on the movement, you use this.

My recommendation. Don't overthink it. Try to use all straps on all sides evenly. Stay neutral. Once you get past a certain skill level, all of this will make a lot more sense and then you can start figuring out more stuff.

To clarify, straps (shtraps) are not an actual muscle or muscle group. Due to a combination of a coffee shortage and my hurried instruction, I had a couple of my students ask me about this. So, the clarification (and misspelling).

To summarise

  • The core's function is to keep your back safe. And to transmit power efficiently.
  • The more efficient it is, the better. Else, you are wasting energy creating power but that's dissipating. Think of the power lines that bring electricity to your home.
  • Pillar is a better term than core. The pillar is a 6-sided box.
    Our pillar is 360 degrees - think of wearing a corset. Plus the bottom. And the top that we are ignoring (for now).
  • The limbs move. The pillar provides a stable pathway.
  • Think of straps running down vertically and diagonally, from shoulder to hip, all around. Tighten the straps (like a backpack strap being tightened, so that the backpack does not jostle) and hold them there and lift/move.

A drill that you can work on is the bird-dog.

And next week

I'll continue this next week, diving into what the heck bracing means. Breathing and bracing are an integral part of all of this and I've conveniently ignored all of it.

Other parts I've left out are tension levels. Keeping the pillar on at a certain tension level varies for each movement - maximum for the deadlift and moderate-to-low for ballistic movements, like a jump.