2. Put your feet together, spread your arms like wings, exhale, lift your right leg forward, and at the same time sweep your arms forward to shoulder height and clamp them like a cat stretching. At this time, there is a feeling of "navel squeezing to the back". Exhale, straighten your back, and then return to your original position. Then repeat the action of your left foot. Left and right once for a complete action, * * * do 20.