Sit-ups, a form of exercise. 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.
Lie on your back on the mat with your knees bent about 90 degrees and your feet flat on the ground. Don't fix your feet on the flat ground (for example, your partner presses your ankles with his hands), otherwise the flexors of thighs and buttocks will also join the work, thus reducing the workload of abdominal muscles.
Furthermore, straight leg sit-ups will increase the burden on the back and easily cause damage to the back. Determine the position of your hands according to the strength of your abdominal muscles, because the closer your hands are to your head, the more difficult it will be to do sit-ups. Novices can put their hands on their sides, and when they get used to it or improve their physical fitness, they can cross their hands on their chests.
Finally, try to cross your hands behind your head, but put your hands on the shoulders on the other side of your body.
Note: Never put your fingers crossed behind your head, so as not to strain the neck muscles when exerting force, and this will also reduce the workload of abdominal muscles.
At the same time, when doing sit-ups, you should cooperate with reasonable breathing. When doing sit-ups, exhale when bending forward and inhale when lying on your back. However, if the whole inhalation process is completed mechanically in the supine state, it is unfavorable for the completion of the action.
Therefore, in order to improve the quality of movement, we must also pay attention to the skills, that is, the process of lying on your back begins to inhale, the shoulder and back contact the pad and gradually lift the upper body. When the upper body is lifted to the abdomen, it quickly exhales and bends forward to complete the movement.