The Elbow Plank is a deceptively difficult isometric, core-building exercise. The key is to keep your body in a static position while your abdomen and back maintain a neutral spine while your arms hold your bodyweight above the ground.
You are not crunching or lifting your legs- simply staying prone and holding the position for as long as you can manage.
Firstly, find yourself a mat or a comfortable area of the floor. Get into a push up position, but with your elbows on the ground instead of your palms. Your face should be looking down and slightly out in front of you. Your legs are extended straight out behind you while your arms are in front with your weight supported on your elbows.
Your hands should be clasped together on the floor beneath your face. Maintain a straight spine, so your legs, back, and head are all in alignment. Inhale and exhale steadily as you use your core to stabilize your body in this position above the ground. Common form mistakes are lifting your hips too high or rounding your lower back inwards.
Keep yourself as stiff as a board throughout the exercise. Try to hold it for as long as 30 seconds. As you become stronger, try to hold the Plank for as long as possible.