Forearm Plank Start face down on the floor resting on your forearms and knees. Push off the floor, raising up off your knees onto your toes and resting mainly on your elbows. Contract your abdominals to keep yourself up and prevent your booty from sticking up. Keep your back flat — don't let it droop or you'll be defeating the purpose. Picture your body as a long, straight board or plank. Image Source: POPSUGAR Photography