I do this thing in cheerleading and it feels like you are doing a toe-touch on the ground. You lay on the ground with your hands clasped behind your head and your legs together. Then you bring them over your head and pull your legs apart. Then you will put them back behind your head and repeat the pulling of arms back and forth and just bring your legs together and out. It works really well! I also we do cheerleading sit ups. Your do five situps or crunches at 0 degrees and then five more at regular sit up style and then at 90 degrees and then your legs all the way up in the air.