(1) Lie flat on your back facing the ceiling, then slowly raise your legs at 90 degrees to your body, and then slowly lower your legs. When you finish, you will feel sore in your abdomen.
You may not be able to do a few at first, but you can do five according to your own situation, and then gradually accumulate.
(2) Lie flat facing the ceiling, then slowly lift your legs, make a 90-degree right angle with your body (taking this as the center), turn five times clockwise and five times counterclockwise. /kloc-after 0/0 laps, it is estimated that your stomach will be very sour.