Leg Raises work your abdominal muscles and your hip flexors. Hip flexors are used for flexing your hips... Duh! This is when you approach your knee to your upper body in any way. Think of sprinting, holding the bottom position of a squat, kicking, and much more. I once injured my hip flexor, this is the reason why I know how important they are. I could not lift my leg 1 inch off the floor!
I've made a video showing you how to perform the different variations of leg raises on parallel bars. When you master straight leg raises on the parallels, start again form the easiest variation hanging from a chin up bar, or anything you can hang from.
Here's the video:
Just add this exercise at the end of your workout, and progress when you are able to do 15 reps. Even with just one set you will progress, no need to do any more.
If you give it a try, keep me posted, and if you have any question, don't hesitate to ask.
To read this post in Spanish, please click here.