Begin about an arm’s length away from the tree. On an inhalation, bring the left arm forward and place the hand on the right side of the trunk. At the same time, extend the right arm behind. On an exhalation, use the hand on the trunk as leverage to twist open to the right — reaching farther behind you with the right arm. Next, on an inhalation, untwist and bring the right arm forward. Place the right hand on the left side of the trunk, and mindfully swing the left arm behind. On an exhalation, use the hand on the tree as leverage again to twist open to the left. Make this movement as fluid as possible as you alternate sides. It should feel as if you are swimming through the air. Practice for several breaths.