Begin by lying down placing your elbows directly under your shoulders and your stomach flat on the floor. Make sure your shoulders and forearms are parallel to each other. Lift yourself up onto your toes and elbows only putting your body into a plank position. Start timing yourself once your back is completely straight. Hold that position for as long as you can or start by timed goals and increasing each rep.
Tip: Make sure you are keeping both your legs and back as straight as you can. And always remember to breathe throughout the entire exercise.