2, the waist is close to the knee, and the action should be slow rather than fast.
3. Slowly lower the upper body when reaching the knees, and repeat when the body forms an angle of 10 degrees with the ground.
4. Another way is to do sit-ups against the wall.
Extended data
1. Gradually increase the number of sit-ups.
For a participant who has just started to train abdominal muscles with sit-ups, the number of sit-ups should not exceed 10 repetitions (train your abdominal muscles first). After each sit-up, stand up or lie down to rest and let the abdominal muscles relax 10 minutes or more.
Do sit-ups slowly.
Mainly for the endurance of abdominal muscles. Therefore, only by doing sit-ups slowly can we really train the endurance of abdominal muscles.
3. The action of sit-ups
The muscles in the upper abdomen of human body mainly include rectus abdominis, external oblique abdominis and internal oblique abdominis. Therefore, if sit-ups are all carried out in the sagittal plane (shoulder-parallel sit-ups), the training effect of external oblique muscle and internal oblique muscle will be obviously limited. Only by increasing the rotation of the longitudinal axis of the body (from the right shoulder to the left leg and from the left shoulder to the right leg) can abdominal muscle training's uncoordinated state be avoided.
In addition to the movements of the upper body, in order to avoid overloading the lower abdominal muscles to bend the hip joint during sit-ups, the knee joint should also bend during sit-ups. However, this supine posture will limit the training effect of lower abdominal muscles after doing sit-up training. Therefore, for middle-aged men and women whose main training area is lower abdominal fat, proper knee bending and leg lifting can train lower abdominal muscles more reliably and achieve the purpose of training abdominal muscles (upper abdomen and lower abdomen).
Baidu Encyclopedia: Matters needing attention in sit-ups