Come onto your hands and knees with hands directly below your shoulders and knees directly below your hips. Inhale to lengthen your spine. Without bending elbows or moving hips, roll your spine forward to arch your back. Lift your chin, chest, and hips to the ceiling, allowing your stomach to sink toward the floor. Once you've reached the fullest expression of your arch, round your spine toward the ceiling and release your head toward the floor. Move in a fluid motion for 5 deep breaths or as many as desired.