The stomach is the abdomen, the abdominal muscles have many muscle groups, including the rectus abdominis, internal oblique abdominal muscles, external oblique abdominal muscles, transverse abdominal muscles, the muscles of the lower back also include the erector spinae muscles and so on, exercise this part of the muscle groups, in fact, the most effective way is the flat support and sit-ups. The flat support on the abdominal muscle taut, the stimulation of the abdominal muscle has a great benefit, because in the process of flat support the abdomen is tense state, is a very tense state, in such a lasting flat support process, the abdominal muscle has been a great exercise. But the flat support to have a gradual process, from twenty seconds to half a minute, a minute, and then to five minutes, the abdomen in slowly become more tight. Do sit-ups in the process, in order to avoid hand extrusion of the cervical spine, causing injury to the spinal cord, you can take the hands vacant such a state to do sit-ups.