– By Barton Tanner
One of the most common sayings across all areas of the fitness industry is when a yoga teacher, lifting coach, Pilates teacher, HIIT trainer, Les Mills Instructor, Dance teacher, boxing coach etc will say; “Turn on your Core muscles”. But what is the ‘Core’ anyway and why do so many people talk about this magical Core?
According to the strict definition, a core is “a central and often foundational part usually distinct from the enveloping part by a difference in nature”. Surprisingly, even though this isn’t an anatomical definition, it is an accurate way to describe what the Core is in the human body.
When your trainers say Core muscles, they are not talking about one muscle, rather a group of muscles that can be found on one neurological pathway. For the human body, the simplest definition of core muscles would be an aerobic group of internal stabilising muscles that contract around the spine and provide a reactionary force that allows our prime movers to move the body.
For example; let’s say you want to move your arm. There are many muscles around the shoulder joint that allow your arm to move. But those muscles need to push against something stable to be able to generate any force in the direction you want your arm to go. In almost all cases, the core will engage to stabilise the spine, which allows you to move your arm.
The Core is a group of 5 muscles that enclose around the lumbar spine: transverse abdominis, pelvic floor muscles, multifidus, diaphragm & posterior fibres of the internal oblique. All of these muscles are aerobic meaning they use oxygen as an energy source and they are containing slow twitch muscle fibres. Think of your core muscles as the endurance athletes of your body. The Core will be engaged pretty much all the time but at a very low intensity. They are not designed for big powerful movements or explosive work but take a long time to fatigue. They are predominantly designed for isometric contractions, the muscle contracts without innovating or moving a joint, but they can also do dynamic contractions.
Our Core muscles are hypersensitive to excitability, meaning we don’t need to do much to engage our core. Balance exercises and exercises on an unstable surface are generally the best ways to get your core firing. The core’s ability to fire is also very closely linked to our proprioception – how the body knows where it is in relation to time and space. Much like the engagement of our core, most of our proprioception happens subconsciously. Yet, this can be tested in one of my favourite core exercises, balancing on one foot with your eyes closed.
So, now you have an understanding of what the Core is you can better understand how it can be trained and what your trainer actually means when they say “engage your core!”