There are multiple terms used to describe activating your core muscles, some examples include; “zip up”, “engage core”, “brace core” and “drawn belly button in”. The best way to learn about your own core is to feel it!
Start by lying on your back with your knees bent up and feet placed on the floor. Place your hands on the front of the bony prominences just below your waist. Then head in toward your belly button by a couple of centimetres to where it’s soft, pictured right.
Now have a cough… you should feel a sheet of muscle push up under your fingers. This is your transversus abdominus. Next you need to try and re-create the sheet of muscle pushing up without coughing. This may take several attempts. I will often get clients to imagine that they are bracing to protect themselves against an object falling onto their stomach or trying to blow up a really stiff balloon. Once you feel a similar pushing up on your hands to when you cough, make this contraction softer, breathe out at the same time and draw up your pelvic floor (this will feel like trying to stop yourself from peeing).
Once you have established the feeling of your core engaging whilst lying on the floor, see if you can acheive the same feeling when standing. A good way of feeling the core working in standing is to do it whilst trying to reach up into a kitchen cupboard. Afterall, the whole point of strengtheing your core is to get it to work better for you day to day in ordinary activities and movements.