Leg lifts is an excellent muscle building exercise that will work out your abdominal muscles. Such an exercise helps your body burn more fat while building more muscle in your abdominal region.
To begin, just lie on the floor flat, with your legs straight out. Lift your legs straight up in the air. Do not bend your knees at all, and make your legs as close to a right angle with your body as possible. Then lower your legs and repeat this movement.
Do not allow your legs to touch the floor. This is a difficult exercise that shows results very quickly. There is some equipment at various gyms that allow you to raise yourself with your arms as support and dangle your legs. This equipment makes the movement easier as all you have to do is raise your knees up to your chest.
Raising your legs to a horizontal position with them straight is very difficult and this equipment helps with that motion. You can try doing leg lifts with a medicine bal