1, curl up, lie flat, legs at 90 degrees, legs flat on the ground. Starting from the shoulder, use the strength of abdominal muscles to slowly lift the upper body and stop at the most uncomfortable position of abdominal muscle contraction. Put it down slowly, but also use the strength of abdominal muscles to put it down in a controlled way. Don't let your shoulders touch the ground. Breathe together and control up and down at a constant speed. You can do 3 groups 10 at the beginning, 20~50 groups 1 after a certain foundation, and then 3~5 groups as needed.

2, sitting on a chair with weight, keeping the back straight, whether it is unarmed or sitting with weight, the body can quickly change the body in a controlled way. Keep the abdominal muscles and back muscles hard for one minute, pay attention to the balance between the left and right, and don't turn loosely for the sake of speed.

3, air bike, lying flat, hands naturally placed on both sides of the body, back close to the ground, one leg straight forward, the other leg tightened the body, as if stepping on the bike in turn. Straighten your legs as close to the ground as possible, and use the strength of the abdominal oblique muscle to tighten and fold your body to the opposite side. Every movement is in place, both sides are balanced and breathing at a constant speed.