Choosing the right method, we must insist on lying on the ground is the best posture, and it will not damage the waist. Abdomen, lie flat on the ground, knees bent 90 degrees, feet flat on the ground. Cross your hands on your chest or beside your ears, tuck your shoulders in, and slightly retract your chin until your shoulder blades leave the ground and your waist is fixed, and then exhale upward and inhale downward, once each time.
The correct way to roll your stomach:
When you lie down, you must exert force on your waist. Relaxing muscles is the most important thing. Lie flat on the floor or yoga mat. Don't lie on the soft bed. Bend your knees, put your legs together and put your feet flat on the ground. Land on your back and relax your neck muscles. Cross your hands on your chest, or put them on your temples. Keep your elbows open and don't touch your head directly.
Pay attention to many problems every time you lift your legs. Don't put too much pressure on the abdomen, reach the highest point of bending, stop for a while, give the abdomen a force, feel the muscles contract, then relax, fall slowly, and finally return to the initial position. This process should also be slowed down, without ups and downs or inertia.