Sit-ups if the movement is not standard, will cause a certain degree of damage to the lumbar spine and cervical spine, the reasons are as follows: First, do sit-ups mainly exercise abdominal muscles, so should make the abdominal muscles throughout the force, avoid borrowing from the iliopsoas muscle, such as iliopsoas muscle borrowing, can lead to lumbar pain symptoms, while doing sit-ups when the cervical spine can not be overflexed, otherwise it will lead to neck pain. Second, do sit-ups when the power is close to exhaustion, usually with the help of explosive force to complete the last few movements, when the waist strength is completely exhausted, the lumbar spine lost lumbar muscle protection, easy to cause lumbar spine injury, the neck is also prone to excessive activity leading to cervical spine injury. To sum up, sit-ups should be standard action, do not use explosive force and inertia to complete the action, otherwise it will cause damage to the cervical and lumbar spine.