What is your core and how should you train it?

The vast majority of people who have worked with me for more than a couple sessions should know two seemingly conflicting things:

1) I almost always disagree with the use of the word “core” (and I despise the common cue to “squeeze your core”)

2) I believe every exercise can, and maybe even should be a core exercise

I’ll explain.

Many people use "abs" and "core" interchangeably. Many fitness professionals will have expanded the definition to, correctly, include the muscles of the lumbar spine.

The core is far more than that, though: technically, it is everything that isn't a limb or your head; so, essentially, your trunk.

The very word "trunk" gives us a clue as to the function of the core: think of a tree, and the qualities of its components. Roots, to anchor into the ground (and seek nutrients and signals from the surroundings). Branches, to spread leaves wide into the sunlight. And a trunk, to connect the two and provide stability and support. The branches and the roots are useless without the connection between them, and that connection won't last long if it isn't stable enough (and flexible enough) to withstand the elements.

Needless to say, the core includes all the muscles of the trunk: the superficial abdominals, the deep abdominals, the little muscles around each vertebra, the big muscles running right down your back, all the muscles in between and around your ribs, but also your pelvic floor muscles, your glutes, and your diaphragm. In other words, it's not just the muscles you see, and it's not just the ones you can "squeeze" (and you certainly can't squeeze them all at once).

Simply put, any time your pelvis needs to be stabilised, you will be engaging core muscles - so any time you are standing, or sitting tall, on all fours, or even lying on your back and performing movement with your limbs, you can and should be using your core muscles. But here’s the thing… the pelvis has muscles that attach to the top of it (the abs you’re undoubtedly thinking of, and the back muscles you probably know are also involved but you’re not sure which ones), but also to the bottom of it: your glutes (the big ones you see and lots of deep ones you don’t), hip flexors (including one of your quad muscles), hamstrings (three of them), and your adductors (four to six of them depending on which source you use). You see now why I say you can’t squeeze them all at once?

So, essentially, even just focussing on breathing is core work. Standing tall with a neutral pelvis is core work. Pressing anything overhead whilst maintaining a neutral spine is core work. Even the much-maligned bicep curl is core work if you're thinking about your posture and your breathing.

Of course, none of those exercises will give you a six-pack; the six-pack muscle is rectus abdominis, and that mostly flexes your spine (as in an abdominal crunch). So it's an important muscle, but it's definitely only a very small part of your core, and crunches should form only a very small part of your "core training".

I’m a strength and conditioning coach: our work begins with a needs analysis; what skills does this person need to complete the tasks their life, job or sport requires? Very few sports, jobs or daily activities require you to be strong with your spine in a flexed (curled over like you’re doing an ab crunch) position; most likely, you’re looking to be able to lift and carry shopping and/or kids (not a personal issue for me, but a very real one for many of my clients!), do bits and pieces around the house and garden, maybe play a sport... activities you will mostly be doing on your feet (or on one foot), often whilst holding or manoeuvring an object (or person) in one hand, changing positions frequently. So you need to be making your core strong when you are on your feet (or, yes, one foot), possibly with an object in one hand, moving through different positions, possibly on uneven or changing terrain.

You also need to make sure your core is strong in these positions whilst allowing you to breathe - for obvious reasons, as well as some slightly less obvious reasons (losing the ability to breathe diaphragmatically results in us overusing muscles in the neck and shoulders to breathe, which can cause tension and pain). If the only way you can stabilise your spine or pelvis (i.e. “engage your core”) is by squeezing your abs, you’re going to have a hard time breathing, let alone diving for a catch or wrangling a writhing child from a car seat.

Of course, there are exceptions: sometimes, you need to isolate a very specific muscle or movement in order to identify it, and learn to switch it on - ab crunches and their variations can be useful here. But in my view, those are not the workout - they are an activation for the workout you actually need to do.

Also, sometimes powerlifters will brace and hold their breath to complete a heavy lift; this is called the valsalva maneuver, and if you are only learning about it in this blog it’s probably not something you should be using.

The key, as always, is intention. What are you working out for? What skills do you need to be good at? In this day and age where nobody seems to have enough time for anything, few things break my heart more than seeing people battle through inefficient workouts: endless squats and step-ups where you are flopping over at the waist, handstand push-ups where your back looks like a banana, punishing runs where your hips are swaying all over the place - all followed by hundreds of crunches and minutes of plank.

By making every exercise a core exercise - i.e., focussing on your posture and what you can feel moving or engaging - you could not only save yourself time and tedium, but also prevent a number of injuries and maximise the impact of your session both in and out of the gym. There’s also evidence that this more focussed (“interoceptive” for my nerdy friends out there) approach could have positive mental health impacts too… but that might be a post for another day ;)