If you want to exercise abdominal muscles, sit-ups can be done in 3 to 8 groups, with about 20 in each group, and the interval between each group is about 30 seconds to 1 minute. The relationship between exercising abdominal muscles is the intensity of the action, and the action should be changed later.

Action posture:

Lie on your back, put your legs together, raise your hand, contract your abdominal muscles, swing your arms forward, and quickly become a sitting position. Keep your upper body bent forward, touch your feet with your hands and bow your head. Then return to the sitting position, and so on.