Start in a side elbow plank on your right side with your feet stacked.
Place your left arm behind your head, and inhale to prepare. (Or, reach your left arm up toward the sky.)
Exhale, engage the deep abs, and rotate your left ribcage toward the floor, bringing your left elbow to your right hand. Hold this a moment, twisting further to deepen your abdominal connection by pulling your navel in toward your spine.
For a more intense burn, reach your left arm under your side body, toward the ground (like this).
Return to the starting position. Emma says, for an extra challenge, lift your hips up about an inch, then come back to neutral.
Repeat for a total of 10 reps, and go directly into the next move before switching sides.