2. Then tilt your feet and put your hands on your thighs;
3. Then push your body forward to your legs and knees with your abdomen;
4. Lean back slightly after touching your knees. At this time, you can't lie down directly, so that the abdomen is always in a state of exertion;
5. After that, the abdominal muscles will push forward to the knees again, and this group of actions can be repeated according to the number of actions set by individual physical strength.