Lie flat on the ground with your knees bent 90 degrees and your 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.

1. Relax your head, grab the feet of the yoga mat with both hands, and pull up the fitness mat when you tuck in. Yoga mats can be replaced by towels, with the waist always attached to the ground and the hips slightly raised.

2. Inhale when lying on your back.

3. Exhale when rolling your abdomen. Reasonable breathing is the key factor to ensure lasting exercise.

PS: During the whole process, the neck is in a relaxed state, and the abdomen contracts when rolled up, especially in the upper abdomen.