Your Most Fundamental Core Exercise
You have a deep set of core muscles: the transverse abdominals, pelvic floor muscles, diaphragm and spinal multifidus muscles. When contracted in sync they make up what’s called the ‘inner core unit’. Correct contraction of these muscle groups creates intra-abdominal pressure (IAP) which makes the torso rigid and fixates/protects the spine. With this correct comtraction you become more biomechanically efficient, becoming more like a shock rebounder rather than a shock absorber; this sets the best platform or anchor point to create ‘all’ your movement against i.e. in every exercise and every set of your resistance training.
Inability to fire up these muscles correctly leaves us ‘outer shell dominant’ meaning we use more superficial muscles to inadequately stabilise our core, our tummy will appear bloated as rectus abdominis, external obliques and erectus spinae handle the forces whilst the inner core remains untrained and un-potentiated. Most people will jump into advanced core exercises without the basic understanding of engaging the inner core unit and so they are left neglected. To make this problem worse people wear weight lifting belts, designed to protect the spine providing IAP externally for extra safety with challenging maximal lifts (1-3 RM), as they train at sub-maximal intensities all the time. This chronic practice will weaken/unstrengthen your core muscles over time and create an ‘external reliance’ on your weights belt (you’ll only be able to lift your current weights whilst supported by the belt). This is typically observed in those folks with ‘all the gear but no idea!’
To fire up the inner core unit, known as bracing or zipping up, we need to contact our pelvic floor muscles located at the base of our pelvis. We activate these muscles the same way we would when stopping ourselves from peeing. Simultaneous we need to also contract our transverse abdominals (TVA), we do this by pulling in our bellybutton towards are spine. When done correctly we should feel pressure build up within our torso and feel our waist narrow. This contraction should not affect our diaphragm and constant breathing should be maintainable. When well practiced you should be capable of contracting & differentiating your inner core unit whilst leaving your outer core muscles disengaged (rectus abdominus & obliques etc).
I regularly test all my clientele to see if they can contract their inner core units properly and measure the IAP they can generate. If they show an initial core dysfunction, then I prescribe daily exercises to facilitate the re-connection to their inner core unit and strengthen it. These exercises are also incorporate into their personalised training.