The whole body lying on the ground, legs together, straight ahead, arms bent at the elbows, both hands resting on the back of the head below the head. Then the right leg bending the knee moderately close the calf, upward bending the knee to lift the left leg, so that the calf and thigh, thigh and the ground are vertical, lift the leg at the same time, the right side of the upper body to the left in front of the back, so that the right side of the shoulder off the ground, the right arm elbow as much as possible to the left knee close to the abdomen to apply force to be pressurized, and then change the side of the action to redo.

legs bent at the knees together, lying on the ground, fully stretched on the ground, arms bent at the elbows, hands holding the head, shoulder blades back, so that the arms try to lean on the ground. Exhale while using the abdomen to exert force, tilt up the upper body, tilt up, chin inward, arms slightly forward, so that the elbows touch the knees, while the feet do not leave the ground, and then slowly lie down to restore the posture, back and forth a few times.

The same is to lie down in a sit-up ready position, legs bent at the knees and together, the size of the legs into 90 degrees, hands on the head, while exhaling while rising above the back, shoulders off the ground, close the chin, but the upper body should not be too much up, do not do it up, as far as possible so that the back of the following, including the lower back and hips to keep on the ground, the two feet should not be away from the ground, the use of the upper abdominal muscles to The first thing you need to do is to use your upper abdominal muscles to complete the tilt-up movement.

lying on the ground, legs bent at the knee and together, left arm bent at the elbow, left hand holding the back of the head, stretch out the right arm, the use of the right hand to stretch forward and abdominal pressure on the two strengths, pulling up the right side of the shoulders off the ground back to the right side of the right hand to touch the left knee on the outside of the right hand, the arm is straight, the right side of the abdomen is especially under pressure, can be strengthened inside and outside of abdominal obliquity muscle strength.