Begin on hands and knees, with the knees under the hips and the hands under the shoulders.
On an exhalation, arch the center of the back up toward the sky, allowing the tailbone and the head to release downward. On the inhale, reverse this spinal movement, allowing the belly to drape downward as the head and tail point upward. Start with a gentle range of motion and repeat for several cycles, expanding the breath movement as you go.
Halfway through the exercise, experiment with switching to an inhale as the back arches upward, then lengthen the spine toward flat on the exhalation. Feel for length in the side bodies and engagement in the abdomen on the exhalation.
Finally, take a few easy breaths with the back flat, feeling for a three-dimensional breath in the whole torso.
Take note of any shifts in your energy, breath, or body awareness. Try to take this awareness with you into the next thing you do.