The humble plank is one of the simplest, yet most effective exercises for strengthening your core. It engages all your core muscles including your six pack and obliques and also works your bum and lower back.
In order to benefit fully from a plank, ensure that you are using correct form every time. Although this is a popular exercise, it is very common to find it being performed incorrectly.
How to:
Begin on your knees on a mat and place your forearms on the mat. Your hands can be placed palms flat on the mat or balled up in a fist on the side, pinkie finger down. Your elbows should be directly beneath your shoulders For added stability, you can keep your feet shoulder-width apart too.
Rise off your knees and extend your feet backwards until your body is parallel to the ground. It is crucial that your keep your back straight, tighten your abs and squeeze your bum. Do not allow your hips to dip to the floor or rise to the ceiling. Your spine should remain neutral throughout with your head looking at your arms.
If you feel your form slipping, stop immediately.