The purpose of fitness is to maintain a healthy state and create a confident, self-empowered self. Imagine how a sound personality can lack fitness? As long as there is fitness that has to mention the spine. The spine is the main bone of the human trunk, with 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae and the sacrococcygeus. The spine I am talking about here does not only include the bones, but also the soft tissues associated with the bones, the nerve tissues, the blood vessels and the lymphatic system. The most important of these are the soft tissues, also known as connective tissues, which are ligaments, tendons, muscles, fascia, etc. What I want to discuss here is not the spine in pathological conditions, but how to maintain a healthy spine during fitness exercises. Today was my second day working out in the neighboring community, and because I went early, there were not many people at the gym. Only a few lesbians were practicing sit-ups. Today’s abdominal muscles are every guy’s dream, and many girls’ dreams, such as Beckham’s six straight abdominal muscles. I observed that when they were trying to sit up, their hands were crossed behind their heads, so that they could keep their bodies straight and act as a fulcrum for the sacrospinal muscles of the trunk when they sat up. In fact, this is not right. 1, sit-up training of the rectus abdominis, the use of sacrospinal muscle fulcrum reduces the work of the rectus abdominis, not a good effect of training; 2, in the hands crossed hard in the back of the head flexion, in fact, in the movement of the cervical spine in a state of forced forward flexion. From the anatomical point of view, the normal forward flexion of the cervical spine is a very important factor in maintaining the normal neurological function of the cervical spine, in some middle-aged people with cervical spine hyperplasia or degeneration do this group of movements, it is likely to make the cervical extensor muscle that is the sacrospinal muscle contusion, or make it easy to spasm, and then the normal forward flexion of the cervical spine disappears to produce symptoms or aggravate the original symptoms of cervical spondylosis. 3, young people in doing this group of exercise is prone to damage the seventh cervical vertebrae, that is, doctors often referred to as the lung spine injury. The seventh cervical vertebra is the augmented vertebra, because its spine compared with other spine is obviously elevated under the skin, so the name augmented vertebra. In extreme flexion of the cervical spine, high tension of the posterior cervical collar ligaments is highly likely to cause acute or chronic avulsion fractures or injuries to the spinous process of the augmented spine; acute avulsions can be referred to as spinous fractures, which are uncommon. It is the chronic injury due to slow periosteal lift that is the cause of chronic neck pain, and such an injury can lead to later calcification or even ossification of the collar ligaments. Therefore, I recommend that during sit-ups, it is important to remember that you should not cross your hands behind your head, but should cross them in front of your chest, which improves the effect of training the rectus abdominis and prevents cervical spine injuries and accidents.