Lift your legs off the ground about a foot, keeping them straight and together.
Begin the exercise by lifting your right leg up towards the ceiling while keeping your left leg a few inches from the ground.
Now, switch your legs, lowering your right leg down a few inches from the ground and lifting your left leg towards the ceiling.
Continue alternating your legs in this manner for your desired number of repetitions, keeping your core engaged and your lower back pressed into the mat throughout the exercise.