In the process of using equipment in the gym, my neck is always stiff and I can't relax. Some people say it's a cervical vertebra problem. Who knows what is going on?
It's normal. It's that the muscles are changing their original habits. Just think about whether you have had such an experience before. For example, I usually eat a bowl of rice, but today I suddenly ate three bowls at once. You must feel sick to your stomach. Exercise should be gradual, and you can't suddenly increase your body's endurance, which will hurt you too much.