The causes of sit-up neck pain are soft tissue strain, cervical spondylosis and so on. 1. Soft tissue strain: when doing sit-ups, you need to pillow your hands behind your head and exert your neck at the same time, if you usually do not have the corresponding exercise, or the neck muscle strength is not enough, it will cause soft tissue strain such as neck muscles and ligaments, and neck pain will occur. 2. Cervical spondylosis: If you usually have cervical spondylosis, such as cervical disc herniation, etc., when you sit up, the cervical spine needs to flex forward, which may lead to the aggravation of cervical spondylosis, so that the nerve root is compressed, which will also cause neck pain. When sit-up neck pain occurs, pay attention to rest, such as after sufficient rest can be recovered, generally do not need special treatment. If the pain is severe, the neck activity is significantly affected, or accompanied by limb numbness and other symptoms, you should go to the hospital in time for further diagnosis and treatment.