Flutter Kicks. How to do it: Lie flat on your back with your arms tucked slightly under your hips with palms facing down. Lift your feet 6 to 8 inches off the floor. Quickly kick (flutter) your legs up and down, raising and lowering your feet only a few inches. Note: to make the exercise easier, raise your legs up higher than the 6 to 8 inches. To make the exercise more difficult, keep your feet closer to the ground.