Lie on your back on the floor with your legs straight up and your knees crossed; Shrink the abdomen and lift the scapula off the ground. The feeling is to move your chest to your feet. Keep your legs in a fixed posture and imagine the feeling of abdominal compression on your spine; Repeat 12— 16 times.

Action 2: Step on the bike.

Lie on your back on the floor with your hands crossed behind your head; Fold your knees to your chest and lift your shoulder blades off the ground; Straighten your left leg at an angle of about 45 degrees with the ground, and twist your upper body to the right at the same time, so that your left elbow is close to your right knee; Change the right leg immediately after returning to the original position, so that the right elbow is close to the left knee, and turn left and right. Repeat like riding a bike 12- 16 times.

Action 3: Stretch your arms and abdomen.

Lying on the mat, your arms are naturally straight to the back of your head, your hands are locked and your arms are against your ears; Abdomen, shoulder blades up; Repeat 12— 16 times.

Action 4: abdomen and buttocks.

Lie on your back on the floor with your hands flat on the floor, or put your arms crossed behind your head; Legs and knees cling to the chest, making it 90 degrees; Abdomen, hips off the ground, legs moving up; The movement range is very small, just lifting the hips without shaking the legs. Repeat 12- 16 times.

Action 5: U-leg extension

Lie on your back on the ground with your legs vertically extended to the ceiling; Gently wrap your hands around your head, tuck in your abdomen, and lift your shoulder blades toward the ceiling; At the same time, the foot is extended and the heel is lifted upwards, and the body shape is U-shaped; Repeat 12— 16 times.