Performing the: A Step-by-Step Tutorial Flutter Kicks
Lift your legs off the ground about 6 inches, keeping them straight and your lower back pressed to the floor.
Begin the exercise by lifting one leg higher (about 45 degrees from the ground), while lowering the other leg closer to the ground, but not touching it.
Then, swiftly switch the positions of your legs, raising the lower leg up and dropping the raised leg down, creating a 'fluttering' motion.
Continue alternating your legs in this manner, keeping your abs engaged and your lower back flat on the floor throughout the exercise.