First, several classic abdominal exercises.
Method 1: Keep lying on your back with your feet shoulder width apart. First, lift your right foot up 10CM, hook your toes in, pause for a second, and then gently put it down, paying attention that your heel can't lean against the bed. When finished, change your left foot and repeat the same action. A set of actions is repeated five times.
Method 2: Lift your right foot to the upper left as far as possible, pause in the air for a second, then put it down, and then change your left foot. Pay attention to the knee can't force, in order to achieve the expected stovepipe effect, and don't strain the leg muscles too reluctantly. Repeat this action 5-7 times.
Method 3: Keep a supine posture, with legs open and shoulder width apart. Bend your arms at a right angle of 90 degrees, stick to the ground, and palm up. Bend your left knee and straighten your upper body so that your right elbow can touch your left knee. Change the right leg, and one group repeats the same action.
Method 4: separate your legs, and the distance between your feet is shoulder width. Inhale and raise your arms horizontally, then exhale, while placing your left hand on your right ankle. Eyes looking at the fingertips of the right hand stretching upward. Inhale again, straighten your upper body, then bend to the other ankle and exhale in the same way. Do it left and right alternately for more than 3 times.