Lying Knee to Chest
Start lying on your back with your legs up and your lower
back completely flat. From there you should slowly bring both of your knees towards your chest and then lower them back down without letting your back come up
Reverse Crunch
Start by lying on your back with your legs bent and lower back flat against the floor. Keep your legs bent and slowly lift them up towards your chest as far as you can and then once they are up in the air you should think about kicking them up higher towards the ceiling. Slowly return back to the starting position and repeat.