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.

Use a slower speed, just like slow-motion playback. When the abdominal muscles pull you up, you have to exhale, so as to ensure that all the muscles deeper in the abdomen participate in the work at the same time.

After the body is off the ground 10 to 20 cm, tighten the abdominal muscles, pause for a while, and then slowly lower the body back to its original position. When your back touches the ground, you can start the next cycle. In the process of sit-ups, the abdominal muscles actually only participate in the work at the initial stage, and then the hip flexors will replace the task.

Extended data

Effect on gastrointestinal tract

Lie on your back, the abdomen and thighs are at 90 degrees, the thighs and calves are at 90 degrees, the body is like a flying fish, and things can be put under the calves. This action looks simple, but to really get the best training effect, you need to "compress" the abdominal muscles with the contraction force of the abdominal cluster, and the action is very short. When doing this, the upper back is off the ground, but the lower back is still close to the ground. The action is just to press the abdomen, bend the spine, and make the chest ribs close to the pelvis. It is just to make the abdominal muscles in a "peak contraction" state, pause for a while, then control the tension of the abdominal muscles, slowly stretch and restore the spine.

Note: The position of hands has a direct influence on the pressure of abdominal contraction.

Usually, there are three different placement positions:

1, hands naturally straight and flat on the side (easy)

2. Don't cross your hands on your chest (in the middle)

Step 3 put your hands behind your neck (difficult)

1. Accurate method: put your hands gently on the back of your neck and ears to avoid the neck from being pressed inward.

2. inaccurate method: hold the back neck tightly with both hands, bend the back and press the neck column inward with both hands.

Can be used for treating gynecological diseases.

First of all, sit-ups can exercise abdominal muscles, tighten abdominal muscles and better protect organs in abdominal cavity. It should be noted that when doing sit-ups, the knee joint can be divided into two postures: straight and bent, and their main functional muscles are different. Straightening the knee to do sit-ups is mainly to exercise the iliopsoas muscle, that is, the iliopsoas muscle (including rectus femoris) contracts when it is far fixed, so that the trunk bends at the hip joint. Bend your knees (bending your knees also produces hip flexion) to do sit-ups, mainly because the rectus abdominis (including the internal and external oblique muscles of the abdomen) contracts when the lower part is fixed, forming the trunk to bend forward and the pelvis to lean forward. Obviously, the flexion of the hip joint makes the iliopsoas muscle contract before the rectus abdominis muscle when preparing for supine posture, and forms the iliopsoas muscle during sit-ups.

Exercise groin

Sit-ups can also exercise the groin. There are many capillaries and acupoints in the groin. Doing sit-ups can stimulate blood vessels in the groin and promote blood circulation in the abdomen through exercise, thus treating and relieving gynecological diseases. At the same time, sit-ups can also stretch back muscles, ligaments and spine, and can adjust the central nervous system by stretching the spine. Moderate exercise can also improve the body's immune function, thus improving the body's disease resistance.

Can reduce stomach

Reducing the stomach needs to cooperate with breathing, and the muscles of the lower abdomen will become tight to achieve the effect of reducing the stomach.

When practicing: exhale in the ascending state (when exerting force) and inhale in the retreating state. Be still, for example, keep an angle of 45 degrees, keep normal chest breathing, and don't hold your breath.

Usually: Abdominal breathing helps to tighten the transverse abdominal muscles. When inhaling, feel the abdominal cavity lift inward and upward, and exhale deeply after inhaling fully. When you sit, stand or walk, you can consciously take abdominal breathing and form a habit.

Slimming principle: This breathing method can ensure that all muscles in the deeper abdomen participate in the work at the same time.

References:

Baidu encyclopedia-sit-ups