Advanced Plank

Lie down on all fours but with your elbows tucked into your sides and forearms resting on the ground and feet together and toes curled in hoisting your body up supporting it from falling. Keeping your back straight and butt up but not overly so with your abs tight. Hold the position there for as long as you can using your abs to hold you up. An advanced movement of the plank is by pulling one leg and the opposite arm in the air while maintaining your body up in the air on one arm and one leg. Switch arms and legs throughout the exercise to work on both sides of the abdominals.