if you want to know some basics about core and its importance, check out my first fitness post. Since I promised to give you a step by step guide on how to employ it, there you go:
Step 1: Initial position
Lie on your back and flex both your legs. Keep your lower back on the ground. Breathe in with your nose and breathe out with your mouth, expanding your stomach to all sides. Be careful not to breathe in your chest. Your lower ribs should not be protruding, try to draw them into your stomach as much as you can. Stay still and keep breathing.
Breathing: If you are having difficulties with correct breathing, put your hand(s) on your stomach. This will help your body to concentrate on breathing in your stomach. You can also press your stomach from both sides with your hands. Slight squeezing of the abdomen will result in its resistance, helping you in the right execution. Your abdomen will tend to inflate more as a whole, rather than excessively moving up and down. The stomach should work as a piston. When it is being inflated, it is expanding to all sides, not only up and down.
Step 2: Activating the core
Keep the initial position and make sure you breathe in to your stomach, keeping your lower back on the ground. Palpate your anterior superior iliac spine and push your index and middle finger about a centimetre right next to it. The easiest way to activate your core is to either laugh or cough. Simply laugh or cough and try to stop and keep it when your abdomen gets hard. Palpating your abdomen, observe the difference in the muscle tension when you cough/laugh or, on the contrary, when you are relaxed. It should vary.
anterior superior iliac spine
No wonder people say that a laughter makes our lives longer. Using your core in everyday life can prevent plenty of health issues (esp. regarding incorrect body posture), thus prolonging our lives.
Step 3: Checking on your activated core
If you managed to activate it and keep the muscle tension, you will not be able to push your fingers into your stomach. However, if you did not, the stomach will be soft and you will be able to easily press them quite deep into it.
Note: Make sure your abdomen is rocklike even while breathing out. Do not relieve it.
Incorrect breathing into chest, soft stomach
Extra step: Still cannot make it work?
Lift your legs above the floor, your hips and knees at a 90 degree angle. This should help to activate it.
As it has been already mentioned, we should have the core engaged prior to our every movement. Do not worry if you do not manage to employ it the first time. Especially if you are a beginner, it is demanding and requires training.
But if you are successful in activating it while lying down, try it in different positions as well, e.g. standing, sitting, walking, running, working out etc.
Hope the guide helps you make it work!