Planks - Prop yourself up into a forearm plank position while lying face down on the ground. Ensure that your elbows are aligned beneath your shoulders and that your hands are fists. You want your forearms to be parallel to each other. Per set, hold for 10 to 20 seconds.
Hanging Leg Raises - To do a proper hanging leg raise, you'll need a pull-up bar above you that you can jump onto with your hands shoulder width apart. Then, while keeping your body straight, rise and lower your legs towards the ceiling. He recommends keeping your legs as straight as possible, however a tiny bend in the knees is acceptable.